求适合下列条件的椭圆的标准方程焦点为F1（0,-1）,F2（0,1）,且B=1

A beautiful world
Hello:
everyone!Now I want to talk about a beatiful world!
When I was young,I always dreamed that I lived in a beautiful country. There were many flowers and trees around our city.We counld hear the birds singing and see the children dancing. The streets were clear and the the air was very fresh! How nice it was!But that only was a dream of mine!How I wish that it would be come true! So I think we should do something to protect our environment. Everyone should make a contribution to protect the environment.
Taking care of our environment is very important.Wherever you live,you can do something around your neighbourhood.
Have you ever thrown any litter onto the ground?Have you ever drawn pictures on public walls?Have you ever spat in a public place?Have you ever cut down trees?If your answers are "No",it means that you have already helped protect our environment.
It is our duty to keep our envionment clean and tidy. You might ask yourself,"Have I ever picked up some rubbish and thrown it into a dustbin?Have I ever collected waste paper or bottles for recycling?Have I ever planted any trees or flowers in or near my neighbourhood?"If your answers are"Yes",it means that you have already done something useful to improve the environment.
Now I want to say :Let`s do our best to make our world more beautiful!
单词量适中,难度适中!

鲁迅先生的书都可以看看.
但对于小学生来讲,还不会理解其内在的深刻含义,只有反复阅读,随阅龄的增长与知识面的扩大,会了解深刻含义.
建议读《野草》《朝花夕拾》.

解题思路：此题隐含的条件是三角形的内角和为180°，列方程，根据已知中角的关系求解，再判断三角形的形状．

∵∠A=[1/2]∠B=[1/3]∠C，
∴∠B=2∠A，∠C=3∠A，
∵∠A+∠B+∠C=180°，即6∠A=180°，
∴∠A=30°，
∴∠B=60°，∠C=90°，
∴△ABC为直角三角形．
故选B．

点评：
本题考点： 三角形内角和定理．

考点点评： 此题主要考查了三角形的内角和定理：三角形的内角和为180°．

熟石灰 ac 物质都是中性的 氢氧化钠是强碱性物质 熟石灰是显碱性的盐 可以用来中和酸性土壤

生物圈是地球上的所有生物与其生存的环境形成的一个统一整体，生物圈的范围：以海平面为标准来划分，生物圈向上可到达约10千米的高度，向下可深入10千米左右深处，厚度为2 0千米左右的圈层，包括大气圈的底部、水圈的大部和岩石圈的表面；大气圈：大气圈是包围地球的气体，由于受地心引力的吸引，以地球表面的大气最稠密，向外逐渐稀薄，过渡为宇宙气体，所以大气圈没有明确的上界．大气圈中生物主要集中于下层，即与岩石圈的交界处． 岩石圈是地球表面的固体部分．它的表面大多覆盖着土壤，是一切陆生生物的“立足点”．在这一圈层内，有郁郁葱葱的森林，一望无际的草原，绚丽多彩的奇花异草，还有五颜六色的昆虫，种类繁多的飞禽走兽，以及大量的细菌、真菌．岩石圈也是人类的“立足点”，在岩石圈中，生物分布的最深记录是生存在地下2500～3000米处石油中的石油细菌，但大多数生物生存于土壤上层几十厘米之内．限制生物向土壤深处分布的主要因素有缺氧和缺光．但人类的活动可以到达生物圈的各个圈层．水圈：由全部的海洋和江河湖泊所组成．分布在地球表面，水圈中几乎到处都有生物，但主要集中于水面以下150米以内．限制生物在深海分布的主要因素有缺光、缺氧和随深度而增加的压力．
故选：C

赤道

我初三了,做作业时经常听歌的,随便什么歌都可以听啊,就是音量稍微小一点,这个可以检测做作业专不专心,专心就听不到了嘛.但做数学的时候最好还是别听了,听的脑子乱了.

　　一,扦插法.也叫插条繁殖.是剪取植物的茎、叶、根等,插入沙土中或浸入水中,促其发生新根而成为一棵独立的新植株.
　　扦插法又可细分为：枝插（用枝条扦插,如月季花等）、叶插（用叶子扦插,如毛叶秋海棠类）、根插（用植物的根扦插）.
　　二、压条法.是把植物的枝条压入土中或用泥土等物包裹,生根后与母株分离,而形成独立新植株的方法.
　　压条法又细分为低压法（将枝条弯曲压入土中,如夹竹桃等.）和高压法（将不易弯曲的枝条割伤或环剥后用沙土进行包裹,如白兰花等）.
　　三、嫁接法.即把甲植物的一部分（接穗）接在乙植物的枝干上（砧木）,使之愈合成为独立新植株.接穗一般是优良品种,经嫁接可以保持其优良特性；砧木一般是野生种,根系发达,生长健壮把优良品种嫁接其上,能使植株生长旺盛.
　　嫁接法可细分为枝接、芽接、靠接和平接等四种.
　　另外还有无性繁殖方法除扦插、压条、嫁接外还有分株法繁殖.即把植物的蘖芽、球茎、根茎、匍匐枝等,从母株上分割下来另行栽植,成为新植株.
　　总而言之,植物开花、授粉、结果,待果实成熟后,用种子进行繁殖叫有性繁殖；而用扦插、压条、嫁接、分株等方法繁殖叫无性繁殖.用种子繁殖可以大量获得新的植株苗；而用扦插等方法进行繁殖新苗 则数量有限.

解题思路：此题涉及了不同物质燃烧产生的效果不同的一道比较题型，从环保、安全等角度进行考虑，解答时可以常用逐一比较排除的方法进行筛选即可．

选项ABD尽管燃烧的产物有二氧化碳或者水，但是它们均有不足之处，即燃烧产物二氧化碳会加重环境中的二氧化碳的含量，加重温室效应．其次，燃烧放出的能量不同．而选项C，H₂-O₂燃料不仅产物是水，无污染．而且氢气的燃烧会放出大量的热，产生巨大的能量．
故选C

点评：
本题考点： 资源综合利用和新能源开发．

考点点评： 解答此题时，应注意比较方法的利用，常用排除法进行筛选即可得出答案．

讨论零点,去绝对值
零点是a=-7/2与a=1/2
(1)当a≤-7/2时,方程化为-4a-6=8
所以a=-7/2不是整数解
(2)当-7/2

面朝大海 春暖花开 海子的

energetic有活力,精力充沛的
natrual自然的,不做作的
talented 有天赋的,有才能的

楼上什么答案?完全不负责任,无语~
生活大爆炸,涵盖面广,语音方面所有美剧基本都非常适合~~

我觉得金山词霸就很方便,如果在电脑上使用的话

just right for walking

D

Compare to him,you may be better for me.

湖北属于亚热带季风气候,总的自然条件还是好的【气候、降水、水文、土壤、植被】可进行立体农业开发.
1.丘陵适合种茶,还可种经济林【一些果树】.
2.山下种一些水稻等粮食作物.还有蔬菜花卉等经济作物.【其中一些要注意轮作、休耕等】
3.如果植被覆盖不好,就植树造林.
土壤若为红壤,会影响产量,那么就要改良土壤.【红壤特性酸、瘦、粘】
希望这些多多少少有用.

Every day we learn in the classroom, one will be able to see the rise of "hard-compliance, respecting teachers, the school loved" the school motto. However, whether or not we thought of ourselves in the end there is not really to "respect for the teaching profession," This is it? ?
Against teachers, it is easy to think of Confucius, the blind writer Helen Keller, etc., they can be called Jesus Christ, name and good willcoexistence, go down in history. And tens of thousands who work in the spirit of open country on the teachers, only because they do not have a celebrity or a great man as the magnificent achievements of their efforts and not known by the conviction on the praise. They work hard, and in the hot sun, in heavy rain, the yield of fruit are also sweet fruit acid fruit, when the community in enjoying the fruits of them, please remember them! ?
The glorious work of the great teachers, has been affirmed and accepted by people. "Village of female teachers," "Spring," "love education" and "last lesson" in the image of teachers has been etched into the hearts of people. However, the aesthetic perspective of a difference there: in a certain distance apart are better things from a closer, it is the one thing. Hence, many people are willing to engage in the profession, does not include teachers. Actually, the flowers and the gardener is zhulianbihe, solidarity, but as a result of teachers and students meet every day, a short distance, and many students of teachers not "to love each other." We are in the habit of "shibiao" standards of teachers, and teachers if not expected, as there are imaginative power, some people will be surprised and even ridicule. I think that teachers are not Superman, but also by no means inferior. As a result of the work of the teachers are real people, not drawings or machine tool life, therefore, teachers have their special work stand, I am afraid not very well understood. ?
Rostrum, the eyes of a teacher's Temple, no longer rostrum than the deprivation of the rights of teachers but also feeling sad and a shame. I am the teacher, but also will not easily give up the podium. Sick leave揣着single rostrum, not advanced in school stories, such a thing as too much. The reasons why, as a female teacher said, real simple: "I am playing a sweater, do not want to let others to play a few half-way into the needle, because everyone is different elastic gesture." This is the case, 365 a year days, regardless of heat or ice cool winter day, the thought of waiting for the class of five looking for a dozen students, teachers will always try to remove all obstacles. A rostrum, he must forget all the pain of all this, the only student in his mind at the moment. Their precious youth to dedicate the podium, in the re-diploma today, they do not have the energy nor time to enjoy the book and then group earned higher diploma, teacher's own ability and experience, the kind of professionalism more than Diploma no life! ?
Let us cherish this wonderful time and treasure to get along with teachers every day.

Yesterday I see the theater is Alice in wonderland, almost all of the audiences are children, content is suitable for children, and so I soon fell asleep.帝国的太阳---Empire of the Sun
Now the Chinese pop music is mostly is sad style, Australia's music is what?
Do you like watching movies?

联立：x-2y+3=0 x+3y-8=0 得：X=7/5 Y=11/5 交点坐标为：（7/5,11/5） 由3x+4y-2=0 得：Y= - 3/4X+1/2 斜率为：- 3/4 根据点斜式得：Y - 11/5= - 3/4(X - 7/5) 整理得：3X+4Y - 13=0

目前不能,虽然有说科学家发现“第二个地球”,但距我们太遥远了.

I'm sorry to remind you that because of the date of the delivery is not sure right now,the shipping fee might be flexible.The price I gived to you is just a reference price.
But trust me please.Our products will meet your requirement; and we will give you our best offer we can.
希望lz满意

English weekly
Bookworm 书虫系列
English Saloon 英语沙龙

有一份报纸.叫做21st century teens因为你还是初中生,所以只能看teens 的.
或者就是英语广场之类了~

The only thing we consider is wether the applicant fits the position, but not his characteristics, religion,race ,marrige state or handicaps.

美森国际少儿英语学校成立于2007年,
专为3到13岁少年儿童提供一流的英语教学服务.
成立之初到如今,经过多年教育经验积累,
已经为广大家长培优出各年龄段英语口语,
英语读写小精英,深受家长推崇,
成为中国儿童英语最具影响力的品牌之一.

I really appreciate the job which the company offered me.However,this job doesn't suit me.I wope you can understand and forgive me.I wish your company a booming business.

一边读一边写,（中文,英文,英文拼写都要念）记单词,不光要会拼写,也要会读平时可以记几个你喜欢的单词,比如：Crazy Boy疯男孩

由7x-m≥0 得 x≥m/7 由6x-n

（我要感谢）课本，她带给我翰墨书香，带给我许多做人的华章；（我要感谢）课桌，她任劳任怨，给我的学习带来方便。（答案不唯一）

I'm not fit for the job which requires a strong ability of logical thinking.

兽炉沈水烟,翠沼残花片,一行行写入相思传.
愁痕满地无人省.
闲阶小立倍荒凉.还剩旧时月色在潇湘.
薄情转是多情累,曲曲柔肠碎.
红笺向壁字模糊,忆共灯前呵手为伊书.

设y=ki；
则有2x^2-5x+3+(-k^2+ki+9)i=0；
2x^2-5x+3-k+(-k^2+9)i=0；
则2x^2-5x+3-k=0且-k^2+9=0；
于是k=-3或k=3；
k=3时,2x^2-5x=0,x=0或x=2.5；
k=-3时,2x^2-5x+6=0,方程无解；
综上x=0或2.5；

Good Boy
Little Robert asked his mother for two cents."What did you do with the money I gave you yesterday?"
"I gave it to a poor old woman," he answered.
"You're a good boy," said the mother proudly."Here are two cents more.But why are you so interested in the old woman?"
"She is the one who sells the candy."
提问：
1Who does Robert ask for money?
2Who did Robert give the money to?
3How much money did Robert give to that guy?

风和太阳(The Wind And The Sun)
One day the wind said to the sun, “Look at that man walking along the road. I can get his cloak off more quickly than you can.”
(有一天风跟太阳说: “看看那个沿着路上走的人.我可以比你快让他把披风脱下来.)
“We will see about that,” said the sun. “I will let you try first.”
(“我们等着看吧,”太阳说, “我让你先试.)
So the wind tried to make the man take off his cloak. He blew and blew, but the man only pulled his cloak more closely around himself.
(因此风尝试让那个人把披风脱下来.他用力地吹,可是那个人把披风拉得更紧.)
“I give up,” said the wind at last. “I cannot get his cloak off.” Then the sun tried. He shone as hard as he could. The man soon became hot and took off his cloak.
(“我放弃了,”风最后说, “我无法让他把披风脱下来.”然后由太阳试试看.他尽可能地晒他.不久,那个人很热就把披风脱下来了.)
这可以吗?

新概念 建议现在多背点好的文章~会很见效的~多读多背 多听磁带 多找机会开口练习 是最有效的英语学习方法

音叉,音叉发出的声音有节奏,声音较为稳定,适合做实验声源.B,靠听到声音的响度判断不是太直观,具有很大的误差,方案不适合； 而测量听不到声音的距离较为直观,具有可靠性； 固体.

利用韦达定理轻松搞定：两根之和x1 + x2 = -b/a = -m,两根之积x1x2 = c/a = m-1
两根之和等于1时,-m = 1,故m = -1.
两根之积等于-1,m-1 = -1,故m = 0.
两根互为倒数,m-1 = 1,故m = 2.
两根互为相反数,-m = 0,故m = 0.

The pink tie fits her very well

《现代汉语词典》2002年增补版中“不偏不倚”的词条解释是：“指不偏袒任何一方,表示公正或中立.也形容不偏不歪,正中目标.”
这句句子里的“不偏不倚”显然是“正中目标”的意思,符合那名画家对模特的要求和标准.
这个词不太有什么别的意思好理解,不贬不褒,上下文语境再怎么变化,词义也不太有可能改变的.

比较推荐《21世纪英语周报》和《疯狂英语》的中学版,两者都比较适合中学生看,前者可以扩散思维,后者比较图文并茂,容易让人感兴趣,可以调节初三的紧张生活.

问题是吸附之后如何再生呢?所以,这种方法用在污水处理上不是好办法.

不知道你说的是不是这个意思.
select '请使用文明语言' from 表 where 字段 like '%粗口1%' or 字段 like '%粗口2%' or 字段 like '%粗口3%'

《初中英语语法全解》是英语周报的主编席玉虎编写的,我感觉还挺不错的,讲解浅显易懂,联系有针对性.还有一本是《赖氏经典英语语法》作者是赖世雄老师,幽默的语言,使学习语法是不显得枯燥!

常用的是SXF-5-12可编程高温炉,SXC-4-13C一体化程控高温炉

S.mile↗雪 S.mile↗鱈 S.mile↗膤 ------------------------- S.mile↗諾 S.mile↗喏 S.mile↗鍩 ----------------------- S.mile↗厷主 S.mile↗肱鉒 S.mile↗厷住 --------------------------- S.mile↗沫 S.mile↗枺 S.mile↗砞
满意请采纳

背时的张老师喊写的对不!我擦,好难写!

Among the various cupboards,my favorite is the one on the lower right corner of the above fig.,which I think it's very fitful to place it in front of the window.This cupboard is suitable for laying some cute toys on it and the color is comfortable.The overall arrangement is good.And it's proper to put it together with the several back cupboards.This kind of cupboard also often can be seen in other places.