海象的寿命大约是40年,海狮得生命比海象的五分之四少2年,海狮的寿命大约是多少年?要过程

C.海豹
熊的主食是 D鲑鱼

鸭嘴兽生的是蛋吃的是奶（小时候）
海马不是鱼吧
儒艮也是海洋哺乳动物 （还有个别名叫“美人鱼”）

这不是牙齿啦,应该是下颌骨的一部分.看不出属于那种,不过应该是某种海豚的.可以肯定不是海象的牙,海象的牙是圆柱形,牙龈更不可能是有关节头滴.

补充： 北极熊在熊科动物家族中属于正牌的食肉动物,它们主要捕食海豹,特别是环斑海豹,此外也会捕食髯海豹、鞍纹海豹、冠海豹.除此之外,它们也捕捉海象、白鲸、海鸟、鱼类、小型哺乳动物,有时也会打扫腐肉.也是唯一主动攻击人类的熊,北极熊的攻击大多发生在夜间.和其他熊科动物不一样的是,它们不会把没吃完的食物藏起来等以后再吃（这倒是大大方便了别的动物,比如懒惰的同类或者北极狐）,甚至时常享用完脂肪之后就扬长而去,要知道对它们而言,高热量的脂肪比肉更为重要,因为它们需要维持保暖用的脂肪层,还需要为食物短缺的时候储存能量.北极熊也不是一点素食不沾,在夏季它们偶尔也会吃点浆果或者植物的根茎.在春末夏临之时,他们会到海边的地方来取冲上来海草补充身体所需的矿物质和维生素物质.

北极熊在陆地上占优势,但北极熊无法用爪子击破海象的皮,也无法击昏2000磅的海象,如果海象将北极熊拖入了大海,海象在海水中是异常灵活的,北极熊的力量也被海水削弱,更致命的是,北极熊得到海面呼吸空气.北极熊在将头升出海面时,身体已经受了海象长牙致命一击,生命也会因此而结束~所以说北极熊不敢公然去捉海象.
在北极熊的食谱中,海象仅限于那些出生不久的;对于成年海象,则敬而远之.

解题思路：鱼类具有用鳃呼吸，用鳍游泳等特征，据此答题．

A、B、D、海狮、海象和海豹尽管都生活在水中，但具有胎生、哺乳的特征属于哺乳动物，而海马生活在水中，有鳍，用鳃呼吸，在水中成直立状前进，属于鱼类．
故选：C

点评：
本题考点： 鱼类的主要特征．

考点点评： 有些动物尽管像鱼，但不是真正的鱼类，要根据其特征来判断．

D、C

哺乳类动物

海狮=40×3/4=30年

海豹=30÷5/6=36年

不懂可追问,有帮助请采纳,谢谢!

海象 [简明汉英词典]
elephant seal
sea elephant
sea ox
sea-ox
walrus

解题思路：根据体内有无脊柱可以把动物分为脊椎动物和无脊椎动物两大类，脊椎动物的体内有由脊椎骨构成的脊柱，无脊椎动物的体内没有脊柱．

题中的动物根据有无脊柱可以分成脊椎动物和无脊椎动物两大类，一类是①海象②热带鱼④鸵鸟⑤巨蟒⑩树蛙属于脊椎动物，海象是哺乳动物，鸵鸟是鸟类，热带鱼是鱼类，巨蟒是爬行动物，树蛙是两栖类；另一类是③沙蚕⑥海葵⑦枯叶蝶⑧乌贼⑨螃蟹属于无脊椎动物，沙蚕是环节动物，海葵是腔肠动物，乌贼是软体动物，枯叶蝶是节肢动物，螃蟹是甲壳动物．
故答案为：

点评：
本题考点： 动物的分类．

考点点评： 掌握动物的分类知识，能正确的对不同的动物进行分类．这部分内容在考试中经常出现，要注意掌握．

海象参加
1
是什么意思？
每个人在北极很兴奋。有将是一个表明，任何人都可以在那。
我会滑冰，北极狐狸说。“我很擅长！'
“我会做翻滚说，北极熊。没有人跌倒，我很喜欢！'
“我去唱歌，说密封。所有人都说我有一个很好的声音！'
然后我会潜水，'说鲸鱼。“我获奖潜水学校，你知道！'
他们都看着海象。你想做什么？他们问。
但海象不擅...

2

解题思路：鱼类具有用鳃呼吸，用鳍游泳等特征，据此答题．

A、海豚、海豹都是哺乳动物，它们都具有胎生、哺乳的特点，故不符合题意；
B、海龟属于爬行动物，海牛属于哺乳动物，故不符合题意；
C、海象属于哺乳动物，海葵属于腔肠动物，故不符合题意；
D、海马、鲸鲨都是终生生活在水中，身体呈梭形，用鳃呼吸，用鳍游泳，是典型的鱼类，故符合题意．
故选：D．

点评：
本题考点： 鱼类的主要特征．

考点点评： 有些动物尽管像鱼，但不是真正的鱼类，要根据其特征来判断．

英文原文：
morse;walrus
英式音标：
[mɔːs] ; [ˈwɔːlrəs; ˈwɒl-]
美式音标：
[mɔːrs] ; [ˈwɔlrəs]

解题思路：先根据海象重量=北极熊重量+0.48吨，求出海象重量，再根据白鲸重量=海象重量+0.12吨即可解答．

0.75+0.48+0.12
=1.33+0.12
=1.45（吨）
答：一条白鲸重1.45吨．

点评：
本题考点： 整数、小数复合应用题．

考点点评： 明确数量间的等量关系，并能根据它们之间的关系，代入数据解答，是此类题目考查知识点．

1大象
2犀牛
3河马
4湾鳄

海豚1天吃36千克,180/36=5

不错的剧本,微有瑕疵,大写改过,仅供参考:
Walrus Joins In 海象参加表演
Narrator：Everyone at the North Pole was very excited.There was going to be a show and anyone could be in it.
Arctic Fox：I will do skating,I’m good at that!
Polar Bear：I’ll do tumbling,no one tumbles quite like me!
Seal：I’ll do singing,everyone says I have a very fine voice!
Whale：Then I’ll do diving.I won a prize for diving at school,you know.
Arctic Fox,Polar Bear,Seal,Whale：(Asked to Walrus) What will you do?
Walrus：(Fell very unhappy,tried to cry) I can’t do anything.
Arctic Fox：Never mind,you can watch us.
Walrus：(Hid behind a snowdrift,speak sadly and quietly) Why CAN I do nothing?
Narrator：At last,the big show arrived.
Arctic Fox：(Skate forwards and backwards and sideways)
Walrus：(Leap onto the ice and join in with Fox) I can skate,look at me!
Narrator：But Walrus couldn’t skate at all.He could only trip up and fall over.He bumped into Fox,and Fox went flat on her face.
Arctic Fox：(Upset) Walrus has ruined my SHOW.
Polar Bear：(Jump and spin and somersault and stand on his hand)
Walrus：(Leap onto the ice) I can tumble too,look at me!
Narrator：But Walrus couldn’t tumble at all.He could only trip up and fall over.He tripped up Polar Bear.
Polar Bear：(Angry) Walrus has ruined my SHOW.
Seal：O,how my heart rejoices when I see the Northern Lights.My ear is filled with voices sweetly singing AT night!(Singing beautifully)
Walrus：I know that song,I can sing it too!(Singing with Seal)
Narrator：But Walrus couldn’t sing at all.He sounded terrible.In fact,he sounded like a rusty old bucket.
Seal：(Burst into floods of tears) Walrus has ruined my song.
Whale：(Leaped high out of the water and fell back with an enormous splash)
Walrus：Everybody,look at me,I can dive too!(Then he leaped into the water)
Narrator：But just at that moment,Whale was getting ready to spout a big jet of water.Whale spouted Walrus high into the air!
Whale：(Furious) You are a meddling,incompetent buffoon!You have ruined my act.Now get out of my sight!
Narrator：The show was over.
Walrus：(Shuffled up to Arctic Fox And Polar Bear and Seal and Whale) I am very sorry.
Arctic Fox：So you should be.
Polar Bear：At least everyone thought you were part of the show.
Seal：If Walrus was really part of our next show,it couldn’t be any worse.
Walrus：(Overjoyed) Me?Truly?Can I be part of the show?Can I join in IT next time?
Whale：Yes.It will be a lot safer that way.You can be the clown.As long as you do it properly.
Narrator：Walrus practiced hard and became part of the show.Sometimes,when Walrus is clowning around,they really just can’t stop themselves.They always shouted like this
Arctic Fox,Polar Bear,Seal,Whale：I can Clown,too,look at me!

翻完了,人工翻得,如果好,楼主给我一百分哦!
每个身处北极的动物都很兴奋,因为这里即将举行一场人人都可以参加的演出.
“我要表演滑雪”北极狐说,“我对此很在行”.
“我要表演翻筋斗”,北极熊说,“没人翻筋斗能比我好”
“我唱歌吧”,海豹说,“每个人都说我嗓音很美.
“那我就表演潜水吧”鲸鱼说,“你们知道,我以前在学校可是拿过潜水奖牌的”
之后大家都看着海象,问他：你表演什么呢?
但是海象什么都不擅长,既不会滑雪也不会翻筋斗.
他的歌唱的很糟糕,而他潜水时,鼻子也是露在水面上的.
于是海象难过的坐在那里,嚼他的胡子.
“没关系”,北极狐说,“你可以看我们表演啊”.
北极狐,北极熊,海豹和鲸鱼都在为那场大型远处而努力练习着,而海象却躲在一个雪堆后面边看着他们,边嚼着他的胡子.
他真希望自己能擅长些什么.
2.盛大的夜晚
终于,表演的盛大夜晚到来了,每个人都坐下来等待演出的开始.
还想坐在最前排,他很激动,狐狸走到冰上向大家示意,众人都欢呼着.
狐狸开始表演滑冰了,他时而前滑,时而后退,时而向两边滑去,他滑出一个优美的圆圈,并8字型的滑着,她的表演简直是无与伦比的完美,海象非常喜欢她的表演,狐狸表演这一切似乎都是那么的简单轻松.
海象认为如果自己也真正的去尝试,一定也能像狐狸表演的那么好.
海象情不自禁的跳到冰上和狐狸一起滑冰“我能滑冰了”他叫嚷着,“快,看我”
然而,海象并没能滑多久,他只是把一切搞砸,摔了一跤,他撞到狐狸,狐狸摔倒压在他的脸上,真糟糕!
狐狸被他搞得心烦.
“海象搞砸了我的演出”狐狸悲叹说
接下来,到了北极熊表演了,他蜷缩起来像一个雪球一样在冰面上滚动,众人都为他鼓掌,然后他就开始准备翻筋斗了,他又跳又滚,翻着筋斗,又倒立.
海象看着北极熊的表演并被深深吸引,他觉得这是时候了,如果他去表演,他也能像北极熊一样翻筋斗.
突然,海象又情不自禁的跳到冰上 “我能翻筋斗了”他叫嚷着,“快,看我”
但是还想根本没能翻筋斗,他只是把一切包扎,摔了下来,搞砸了北极熊的表演.
当然,北极熊也非常生气,“海象搞砸了我的演出”他悲叹的说.

North Pole was going to be a show and anyone could be in it.
Arctic Fox are going to do skating ,andPolar Bear are going to do tumbling. Seal will sing.Whale are going to do diving .But Walrus was not good as anything .
At last,the big night arrive .Everyone make their best ,but only Walrus ,when anyone act Walrus all ruined their act .
So,every was angry,but,there are going to snow ,everyone was happy ,And walrus practice haidly and hardly .
Somtimes ,when walrus is clowning around,everyone was join in too!

果断企鹅

walrus
wal=wall
rus=r+us
然后连一起哦~
U等于拼音里a的发音~
可以查一下自然发音法哦 见词就能读了~

解题思路：[2/3]的单位“1”是海狮的寿命，求海豹的寿命，也就是求海狮寿命的[2/3]是多少年，所以必须先求出海狮的寿命，[3/4]的单位“1”是海象的寿命，是已知的，求海狮的寿命，也就是求40年的[3/4]是多少，进而列式解答即可．

海狮的寿命：40×[3/4]=30（年），
海豹的寿命：30×[2/3]=20（年）；
综合算式：40×[3/4×
2
3]，
=30×[2/3]，
=20（年）；
答：海豹的寿命大约是20年．

点评：
本题考点： 分数乘法应用题．

考点点评： 此题属于含有两个单位“1”的分数连乘应用题，解答关键是从问题入手分析，要求什么，必须先求什么，把什么看作单位“1”，确定好分率对应的具体的数量．

CD

Walrus Joins In
1
What will Walrus do?
Everyone at the North Pole was very excited.There was going to be a show and ANYONE could be in it.
鈥業 will do skating,鈥 said Arctic Fox.鈥業鈥檓 good at that!鈥橖br/>鈥業鈥檒l do tumbling,鈥 said Polar Bear.鈥楴o one tumbles quite like me!鈥橖br/>鈥業鈥檒l do singing,鈥 said Seal.鈥楨veryone says I have a very fine voice!鈥橖br/>鈥楾hen I鈥檒l do diving,鈥 said Whale.鈥業 won a prize for diving at school,you know!鈥橖br/>They all looked at Walrus.鈥榃hat will YOU do?鈥 they asked.
But Walrus was not good at anything.
He wasn鈥檛 good at skating,and he wasn鈥檛 good at tumbling.
He was terrible at singing,and when he tried to dive,he always got water up his nose.
He sat and chewed his whiskers sadly.
鈥楴ever mind,鈥 said Arctic Fox.鈥榊ou can watch us.鈥橖br/>Arctic Fox and Polar Bear and Seal and Whale practised hard for the big show.
Walrus hid behind a snowdrift and watched,and chewed his whiskers.
He wished he was good at something.
2
The big night
At last,the big night arrived.Everyone sat down and waited for the show to begin.Walrus sat in the front row.He was very excited.
Fox came onto the ice and bowed.Everyone cheered.
Then Fox began to skate.Fox skated forwards and backwards and sideways.She skated in perfect circles and figures of eight.She was elegant and amazing!
Walrus watched and he loved what he saw.Fox made it all look so easy.
Walrus was sure that if he really tried he could skate just like Fox.
He couldn鈥檛 stop himself.He just had to leap onto the ice and join in with Fox.鈥淚 can skate,鈥 he cried.鈥淟ook at me!鈥滭br/>But Walrus couldn鈥檛 skate at all.He could only trip up and fall over.
He bumped into Fox,and Fox went flat on her face.FLOMP!
Fox was very upset.鈥淲alrus has RUINED my act,鈥 she wailed.
Next,it was Polar Bear鈥檚 turn.He rolled out across the ice like a big,white snowball.Everyone clapped wildly.
Then Polar Bear began to tumble.He did jumps and spins and somersaults,and stood on his head.
Walrus watched and he loved what he saw.Polar Bear made it all look such fun.Walrus was sure that this time,if he really tried,he could tumble just like Polar Bear.
All of a sudden,Walrus just couldn鈥檛 stop himself,and he leaped onto the ice.
鈥淚 can tumble too,鈥 he cried.鈥淟ook at me!鈥滭br/>But Walrus couldn鈥檛 tumble at all.He could only trip up and fall over.He tripped up Polar Bear,who came down with a WALLOP!
Of course,Polar Bear was pretty angry.鈥淲alrus has RUINED my act,鈥 he wailed.
3
From bad to worse
It was Seal鈥檚 turn next.She gave Walrus a don鈥檛-you-dare stare,and then she started to sing:
鈥淥,how many heart rejoices when I see the Northern Lights.
My ear is filled with voices sweetly singing in the night!鈥滭br/>Walrus listened.What a beautiful song!Surely if he really tried,he could sing as beautifully as Seal?Oh,dear.Walrus just couldn鈥檛 stop himself again.
鈥淚 know that song,鈥 he cried.鈥淚 can sing it too!鈥滭br/>He leaped up and started singing along with Seal.
But Walrus couldn鈥檛 sing!He sounded terrible.In fact,he sounded like a rusty old bucket.
Seal stopped singing and burst into floods of tears.
鈥淲alrus has RUINED my song,鈥 she wailed.
Wale was last.He was pretty certain that Walrus could not ruin his act.
Whale leaped high out of the water.Then he fell back with an enormous splash!
Walrus watched.He wished that he could dive like that.His flippers began to twitch,and his whiskers bristled with excitement.He tried and tried his very best not to join in.
But then he had a brilliant idea.
鈥淚鈥檒l hold my nose when I dive,鈥 he thought.鈥淭hen the water won鈥檛 go up it!鈥滭br/>Walrus just couldn鈥檛 stop himself.He had to join in.
鈥淓verybody,look at me!鈥 he cried,as he leaped into the water.鈥淚 can dive too!鈥滭br/>But just at that moment,Whale was getting ready to spout a big jet of water.
WHOOSH!
Whale spouted Walrus high into the air!
Everyone was watching Walrus now.They clapped and cheered as Walrus landed back in the sea with a SPLOSH!
Whale was furious.鈥淵ou are a meddling,incompetent BUFFOON!鈥 he roared.鈥淵ou have RUINED my act.Now GET OUT OF MY SIGHT!鈥
Whale was pretty scary when he was angry.Walrus turned tail and fled.He hid behind a snowdrift,feeling sad and very sorry.
4
The show will go on!
The show was over.Fox and Polar Bear and Seal and Whale stood in a line,blushing and wishing that Walrus had not ruined everything.
But everyone was cheering like mad.
鈥淲ell done,Polar Bear,well done,Seal!Well done,Fox and Whale!鈥 they shouted.鈥淏ut where鈥檚 the clown?Why isn鈥檛 he here?Where鈥檚 Walrus?鈥滭br/> Behind is snowdrift,Walrus heard the cheers.Were they really cheering for him,too?
Yes!They were!
He shuffled up to Fox and Polar Bear and Seal And Whale.
鈥淚鈥檓 very sorry,鈥 he said.
鈥淪o you should be,鈥 said Fox.
鈥淎t least everyone thought you were part of the show,鈥 said Polar Bear.
鈥淚 suppose,鈥 said Seal,鈥渋f Walrus was really part of our next show,it couldn鈥檛 be any worse.鈥滭br/>Walrus was overjoyed.鈥淢e?鈥 he cried.鈥淭ruly?Can I be part of the show?Can I join in next time?鈥滭br/>鈥淵es,鈥 said Whale.鈥淚t will be
a lot safer that way.You can be the clown.As long as you do it properly.鈥滭br/>Walrus practiced hard and became a very good clown indeed.Now he is so good that Fox,Polar Bear,Seal and Whale are glad he is taking part.
Sometimes,when Walrus is clowning around,they really just can鈥檛 stop themselves.They have to join in too!

The arrival of the new star Walruses in the zoo attracts lots of visitors.

由快到慢
第一组,羚羊、松鼠、猴子
第二组,牦牛、大象、海象

这句话用了打比方的说明方法

D

南极磷虾是生活在南大洋中的一种甲壳类浮游动物,个体不大,体长一般3～5厘米.但是蕴藏量却十分惊人,约4～6亿吨,也有一种说法认为有50亿吨.它在南大洋食物链中起着重要作用,是海豹、鲸和企鹅的食物,也是重要的海洋生物资源.
所以选A!

The most resistant to the high-pressure life
In the ocean,the deeper the depth of the sea,the pressure will be greater the biological but also the more could not survive.Marine mammals such as walrus and sperm whales can dive to depths over 1000 m.However,this is their limit,and then down the water pressure is the atmospheric pressure a few times,that kind of pressure,due to the cell membrane being squeezed,nerve and heart muscle of the marine life will not work!Incredible,even at 10,000 meters below the seabed - the world's deepest trench,the Mariana Trench,where for many years the only eternal darkness,the living environment even more than the surface of Venus is even worse,where the water pressure is surface atmospheric pressure of 1000 times.Many scientists believe that the kind of place can not be life,but there did survive some strange fish and shrimp.
谷歌翻译

原文：Every living in the Arctic animals are excited,because it will soon hold a performance that everyone can participate.
"I want to show skiing," Arctic Fox said,"I am very good at."
"I want to perform somersaults," polar bear said,"No one can be better than me tumbling"
"I sing it," Seals said,"Everyone says I'm beautiful voice.
"Then I'll show dive bar," Whale said,"You know,I used to dive in the school but took a medal"
After all look at the walrus,asked him:What do you perform?
But nothing good walrus,neither ski will not tumble.
His singing is very bad,and he dives nose is exposed on the surface of the water.
So sad walrus sitting there,chewing his beard.
"Never mind",the Arctic fox said,"You can watch our show,ah."
Arctic foxes,polar bears,seals and whales in the distance for the large-scale efforts that field practicing,and walrus are hiding behind a snow bank,looking at them,while chewing his beard.
He wished he could good at something.
Big night
Finally,the grand performance came at night,everyone sat down to wait for the show begin.
Would also like to sit in the front row,he was excited to tell you to indicate the fox went to the ice,and everyone cheered.
The fox began to show skating,and he sometimes forward slip,sometimes back,sometimes to both sides of the slide,he slid off a beautiful circle,and 8-shaped slide,her performance is simply unmatched perfection,like her walrus show,fox show it all seems so simple and easy.
Walrus is also true that if they try,will also perform as good as the fox.
Walrus can not help but jump on the ice and skate with the fox,"I can skate," he cried,"Quick,look at me"
However,no walruses can slide long,he just all screwed up,fall,and he hit the fox,the fox fell down on his face,what a shame!
He do a fox was upset.
"Walrus messed up my performance," bemoaning fox
Next,to show the polar bear,and he curled up like a snowball rolling on the ice as the crowd clapped for him,and then he began to prepare tumble,and he jump and roll,turning somersaults,and handstands.
Walrus polar bear looked at the performance and was deeply attracted to and he thought it was time,if he went to show,like the polar bear as he can tumble.
Suddenly,the walrus and can not help but jump on the ice "I can tumble," he cried,"Quick,look at me"
But did not want to tumble,he just put all the dressing,and fell down,messed up the polar bear show.
Of course,the polar bear is very angry,"Walrus messed up my performance," he lamented to say.
译文：每个身处北极的动物都很兴奋,因为这里即将举行一场人人都可以参加的演出.
“我要表演滑雪”北极狐说,“我对此很在行”.
“我要表演翻筋斗”,北极熊说,“没人翻筋斗能比我好”
“我唱歌吧”,海豹说,“每个人都说我嗓音很美.
“那我就表演潜水吧”鲸鱼说,“你们知道,我以前在学校可是拿过潜水奖牌的”
之后大家都看着海象,问他：你表演什么呢?
但是海象什么都不擅长,既不会滑雪也不会翻筋斗.
他的歌唱的很糟糕,而他潜水时,鼻子也是露在水面上的.
于是海象难过的坐在那里,嚼他的胡子.
“没关系”,北极狐说,“你可以看我们表演啊”.
北极狐,北极熊,海豹和鲸鱼都在为那场大型远处而努力练习着,而海象却躲在一个雪堆后面边看着他们,边嚼着他的胡子.
他真希望自己能擅长些什么.
盛大的夜晚
终于,表演的盛大夜晚到来了,每个人都坐下来等待演出的开始.
还想坐在最前排,他很激动,狐狸走到冰上向大家示意,众人都欢呼着.
狐狸开始表演滑冰了,他时而前滑,时而后退,时而向两边滑去,他滑出一个优美的圆圈,并8字型的滑着,她的表演简直是无与伦比的完美,海象非常喜欢她的表演,狐狸表演这一切似乎都是那么的简单轻松.
海象认为如果自己也真正的去尝试,一定也能像狐狸表演的那么好.
海象情不自禁的跳到冰上和狐狸一起滑冰“我能滑冰了”他叫嚷着,“快,看我”
然而,海象并没能滑多久,他只是把一切搞砸,摔了一跤,他撞到狐狸,狐狸摔倒压在他的脸上,真糟糕!
狐狸被他搞得心烦.
“海象搞砸了我的演出”狐狸悲叹说
接下来,到了北极熊表演了,他蜷缩起来像一个雪球一样在冰面上滚动,众人都为他鼓掌,然后他就开始准备翻筋斗了,他又跳又滚,翻着筋斗,又倒立.
海象看着北极熊的表演并被深深吸引,他觉得这是时候了,如果他去表演,他也能像北极熊一样翻筋斗.
突然,海象又情不自禁的跳到冰上 “我能翻筋斗了”他叫嚷着,“快,看我”
但是还想根本没能翻筋斗,他只是把一切包扎,摔了下来,搞砸了北极熊的表演.
当然,北极熊也非常生气,“海象搞砸了我的演出”他悲叹的说.

Every living in the Arctic animals are excited,because it will soon hold a performance that everyone can participate.
"I want to show skiing," Arctic Fox said,"I am very good at."
"I want to perform somersaults," polar bear said,"No one can be better than me tumbling"
"I sing it," Seals said,"Everyone says I'm beautiful voice.
"Then I'll show dive bar," Whale said,"You know,I used to dive in the school but took a medal"
After all look at the walrus,asked him:What do you perform?
But nothing good walrus,neither ski will not tumble.
His singing is very bad,and he dives nose is exposed on the surface of the water.
So sad walrus sitting there,chewing his beard.
"Never mind",the Arctic fox said,"You can watch our show,ah."
Arctic foxes,polar bears,seals and whales in the distance for the large-scale efforts that field practicing,and walrus are hiding behind a snow bank,looking at them,while chewing his beard.
He wished he could good at something.

海狮因它的面部长得象狮子而得名 海象科Odobenidae仅包括海象Odobenus rosmarus一种,是特产于北冰洋海域的海兽,因犬齿发达似象牙而的名

两栖动物除了青蛙还有山龟、山鳖、石蛙、和鲵鱼（娃娃鱼） 蟾蜍 龟 鳄鱼 蜥蜴 蛇
他们的特征是：身体表面裸露（没有毛、鳞、甲等覆盖）是两栖动物身体的特征,卵生、变态是两栖动物在繁殖和生长发育方面的特征.凡是具有这两方面特征的动物,都属于两栖动物.
海象和海豹就不是啦!

解题思路：鱼类具有用鳃呼吸，用鳍游泳等特征，据此答题．

A、B、D、海狮、海象和海豹尽管都生活在水中，但具有胎生、哺乳的特征属于哺乳动物，而海马生活在水中，有鳍，用鳃呼吸，在水中成直立状前进，属于鱼类．
故选：C

点评：
本题考点： 鱼类的主要特征．

考点点评： 有些动物尽管像鱼，但不是真正的鱼类，要根据其特征来判断．

20%

Walrus Joins In
1
What will Walrus do?
Everyone at the North Pole was very excited.There was going to be a show and ANYONE could be in it.
„I will do skating,‟ said Arctic Fox.„I‟m good at that!‟
„I‟ll do tumbling,‟ said Polar Bear.„No one tumbles quite like me!‟ „I‟ll do singing,‟ said Seal.„Everyone says I have a very fine
voice!‟
„Then I‟ll do diving,‟ said Whale.„I won a prize for diving at school,you know!‟
They all looked at Walrus.„What will YOU do?‟ they asked.But Walrus was not good at anything.
He wasn‟t good at skating,and he wasn‟t good at tumbling.
He was terrible at singing,and when he tried to dive,he always got water up his nose.
He sat and chewed his whiskers sadly.
„Never mind,‟ said Arctic Fox.„You can watch us.‟
Arctic Fox and Polar Bear and Seal and Whale practised hard for the big show.
Walrus hid behind a snowdrift and watched,and chewed his whiskers.
He wished he was good at something.
2
The big night
At last,the big night arrived.Everyone sat down and waited for the show to begin.Walrus sat in the front row.He was very excited.Fox came onto the ice and bowed.Everyone cheered.
Then Fox began to skate.Fox skated forwards and backwards and sideways.She skated in perfect circles and figures of eight.She was elegant and amazing!
Walrus watched and he loved what he saw.Fox made it all look so easy.
Walrus was sure that if he really tried he could skate just like Fox.
He couldn‟t stop himself.He just had to leap onto the ice and join in with Fox.鈥淚 can skate,鈥 he cried.鈥淟ook at me!鈥滭br/>But Walrus couldn‟t skate at all.He could only trip up and fall over.
He bumped into Fox,and Fox went flat on her face.FLOMP!Fox was very upset.鈥淲alrus has RUINED my act,鈥 she wailed.Next,it was Polar Bear‟s turn.He rolled out across the ice like a big,white snowball.Everyone clapped wildly.
Then Polar Bear began to tumble.He did jumps and spins and somersaults,and stood on his head.
Walrus watched and he loved what he saw.Polar Bear made it
2/6
all look such fun.Walrus was sure that this time,if he really tried,he could tumble just like Polar Bear.
All of a sudden,Walrus just couldn‟t stop himself,and he leaped onto the ice.
鈥淚 can tumble too,鈥 he cried.鈥淟ook at me!鈥滭br/>But Walrus couldn‟t tumble at all.He could only trip up and fall over.He tripped up Polar Bear,who came down with a WALLOP!
Of course,Polar Bear was pretty angry.鈥淲alrus has RUINED my act,鈥 he wailed.
3
From bad to worse
It was Seal‟s turn next.She gave Walrus a don‟t-you-dare stare,and then she started to sing:
鈥淥,how many heart rejoices when I see the Northern Lights.My ear is filled with voices sweetly singing in the night!鈥滭br/>Walrus listened.What a beautiful song!Surely if he really tried,he could sing as beautifully as Seal?Oh,dear.Walrus just couldn‟t stop himself again.
鈥淚 know that song,鈥 he cried.鈥淚 can sing it too!鈥滭br/>He leaped up and started singing along with Seal.
But Walrus couldn‟t sing!He sounded terrible.In fact,he sounded like a rusty old bucket.
3/6
Seal stopped singing and burst into floods of tears.
鈥淲alrus has RUINED my song,鈥 she wailed.
Whale was last.He was pretty certain that Walrus could not ruin his act.
Whale leaped high out of the water.Then he fell back with an enormous splash!
Walrus watched.He wished that he could dive like that.His flippers began to twitch,and his whiskers bristled with excitement.He tried and tried his very best not to join in.
But then he had a brilliant idea.
鈥淚‟ll hold my nose when I dive,鈥 he thought.鈥淭hen the water won‟t go up it!鈥滭br/>Walrus just couldn‟t stop himself.He had to join in.
鈥淓verybody,look at me!鈥 he cried,as he leaped into the water.鈥淚 can dive too!鈥滭br/>But just at that moment,Whale was getting ready to spout a big jet of water.
WHOOSH!
Whale spouted Walrus high into the air!
Everyone was watching Walrus now.They clapped and cheered as Walrus landed back in the sea with a SPLOSH!
Whale was furious.鈥淵ou are a meddling,incompetent BUFFOON!鈥 he roared.鈥淵ou have RUINED my act.Now GET OUT
4/6
OF MY SIGHT!鈥滭br/>Whale was pretty scary when he was angry.Walrus turned tail and fled.He hid behind a snowdrift,feeling sad and very sorry.
4
The show will go on!
The show was over.Fox and Polar Bear and Seal and Whale stood in a line,blushing and wishing that Walrus had not ruined everything.But everyone was cheering like mad.
鈥淲ell done,Polar Bear,well done,Seal!Well done,Fox and Whale!鈥 they shouted.鈥淏ut where‟s the clown?Why isn‟t he here?Where‟s Walrus?鈥滭br/>Behind his snowdrift,Walrus heard the cheers.Were they really cheering for him,too?
Yes!They were!
He shuffled up to Fox and Polar Bear and Seal And Whale.
鈥淚‟m very sorry,鈥 he said.
鈥淪o you should be,鈥 said Fox.
鈥淎t least everyone thought you were part of the show,鈥 said Polar Bear.
鈥淚 suppose,鈥 said Seal,鈥渋f Walrus was really part of our next show,it couldn‟t be any worse.鈥滭br/>Walrus was overjoyed.鈥淢e?鈥 he cried.鈥淭ruly?Can I be part ofthe show?Can I join in next time?鈥滭br/>鈥淵es,鈥 said Whale.鈥淚t will be a lot safer that way.You can be the clown.As long as you do it properly.鈥滭br/>Walrus practiced hard and became a very good clown indeed.Now he is so good that Fox,Polar Bear,Seal and Whale are glad he is taking part.
Sometimes,when Walrus is clowning around,they really just can‟t stop themselves.They have to join in too!

North Pole was going to be a show and anyone could be in it.
Arctic Fox are going to do skating ,andPolar Bear are going to do tumbling.Seal will sing.Whale are going to do diving .But Walrus was not good as anything .
At last,the big night arrive .Everyone make their best ,but only Walrus ,when anyone act Walrus all ruined their act .
So,every was angry,but,there are going to snow ,everyone was happy ,And walrus practice haidly and hardly .
Somtimes ,when walrus is clowning around,everyone was join in too!

少=(15-12)÷15=20%

不懂可追问,有帮助请采纳,谢谢!

20

2.海象的寿命大约是40年,海狮的寿命是海象的4分之3,海豹的寿命是海狮的3分之2.海豹的寿命大约是多少年?
40×4分之3×3分之2
=30×3分之2=20

1.沙丁鱼 Sardines
2.鲸鱼 Whales
3.海龟 Turtle
4.Crab
5.Hippocampal
6.Haishi
7.Walrus
8.Starfish
9.Seals
10.Cuttlefish
11.Octopus
12.Sharks
13.Lobsters
14.Penguins
15.Polar bear
16.Blowfish
17.sturgeon
18.swordfish
19.piranha
20.Squid

海狗属于海狮科,它和海豹的差别为:海狗的鳍状后肢可朝向前方,所以能够在陆地上行走,而海豹则不能.此外,有如小指头...海狗很像海狮,全身覆有绒毛,脸很短是其特徵.海狗与海狮不同,但因为它们的皮毛柔软、漂亮,往往招致猎人...
其它的区别就比较简单了

1、40乘以75%=30年
答：海狮的寿命大约是30年.
2、40乘以（1-25%）=30年
3、40乘以（3/4）=30年

选D.鲸鱼x04x03x04x03鲸 x04x03 北极最大的鲸是格陵兰鲸,其身长20米～22米,体重可达150吨.刚出生的小鲸一般有三四米长,重两吨左右.母鲸对它的孩子十分抚爱,遇到危险时就用自己的身躯保护小鲸,并发狂地挡住捕鲸船的攻击.北极有一种形体较小、长相奇特的鲸叫一角鲸,体长仅4米～5米,重约900公斤～1500公斤.它的体形很奇特,头上长着一个约1米～2米的角.当地居民给它起了一个浑名,叫它独角兽.其实,一角鲸的“角”不是角,而是大牙,也有人称它一齿鲸.人们研究一齿鲸特别对奇长的牙齿生理作用的研究,已有上百年的历史.

南极磷虾是生活在南大洋中的一种甲壳类浮游动物,个体不大,体长一般3～5厘米.但是蕴藏量却十分惊人,约4～6亿吨,也有一种说法认为有50亿吨.它在南大洋食物链中起着重要作用,是海豹、鲸和企鹅的食物,也是重要的海洋生物资源.
becuas选A!

这是小学作业吧,给你解答思路,把企鹅设成X,那么海豹,海狮,企鹅都可以用x来表示,最后四种动物的和等于310,是一个一元一次方程,可以求解了,答案我就不算了,还是自己多动动手好