最近在英语学习上遇到一些困难 在这里先谢谢了

设百分率为a 2.25%×(1-a)=1.96% （1-a)=196/225 1-a=14/15 a=1/15=6.67% 百分率为6.67%

解题思路：通过理解题意可知本题的等量关系，即峰电电费+峰谷电费=115．根据这个等量关系，可列出方程，再求解．

设用峰电x千瓦时，则有0.55x+0.30×（300-x）=115，
解得：x=100．
∴王老师家该月使用“峰电”100千瓦时．

点评：
本题考点： 一元一次方程的应用．

考点点评： 解题关键是要读懂题目的意思，根据题目给出的条件，找出合适的等量关系，列出方程，再求解．

有两种可能 第一,你是不是做了什么事想蛮她但被发现了 第二,是她自己的问题,也许受到外界压力等原因,让自己对外界的一切都保持警觉 比如一只受伤的兔子

半人马星座4.17光年

I'm feeling pretty good lately!
or
I'm in a good mood lately.(必须有a)

水星

当水被加热后,碳酸氢钙就会分解出来,变成细小的碳酸钙沉淀物.用水壶烧开水时,这些沉淀物会贴在水壶的底部,久而久之就形成了水垢.
在大自然中的水或多或少都含有一种叫碳酸氢钙的化学物质.这种物质溶在水里,眼睛是看不见的.但是当水被加热后,它就会分解出来,变成细小的碳酸钙沉淀物.用水壶烧开水时,这些沉淀物会贴在水壶的底部,久而久之就形成了水垢.
水垢是时间久了才会形成的

你应该多找点题目多看看题型,我现在也是这样的.所以我每天都会看10分钟的数学题

应该是：最近全国各地加大了对醉酒驾车的惩处力度,为的是那些骇人听闻的交通事故不再发生.
去掉避免二字即可

可以改成：
1、最近全国各地加大了对醉酒驾车的惩处力度,为的是避免那些（骇人听闻）的交通事故再发生.
2、最近全国各地加大了对醉酒驾车的惩处力度,为的是那些（骇人听闻）的交通事故不再发生.
病因：词语打错、意思重复.

i am not sure.
take 15 minutes by+交通工具
it is easy to arrive at school
be afraid of doing sth
he treats me like my father
it isn't a bridge here
nearest mail
distance taking by bus
long journey
kilometer
pass
alive
cross
many

该核素的衰变性质保证了其化学性质实验获得成功.
要发生化学反应,则该核素半衰期必须要长,否则会发生衰变不能反应,以此为判断,只有半衰期9.3S的才是正确的
然后X质子数为12+96=108,X为Hs
质量数和质子数写法见方程式的图
方程式附图（图片被限制了大小,看得不清晰请见谅）

|

Dear old dad:
The most into work also satisfactory?
I know, you have to notice body with more so. You always say no, but I know you always hard take hold. Dad, I recently doesn't study labor, always make you angry, but you rest assured, I will still be hard. 6 grade, and quick breath, and I'm afraid I I failed, afraid you accuse me. I know, you to my hope is very big, this just makes me under a lot of pressure, be afraid of failed to live up to your hope. Dad sometimes you see I make a mistake, always sees with one eye closed and with one eye, are you sure you want to: child, always make mistakes. But I very want to hard to make mistakes, but I'm always no. I know I have a lot of shortcomings, I am trying to correct, I hope you understand!
Finally I wish dad: healthy, everything goes well, success in work!
Your son

Excuse me,where is the nearest hotel?

埃及的金字塔可是个难点,很吸引人

1.Amy's mother is ill in hospital.She has to look after her.
2.Do you know the way to the nearest sports shop?
3.The three men in poilce uniforms pushed them into the lorry and drove away.
4.Bob is trying to open the backdoor of the lorry with a knife.
5.I'm afraid he won't come to this party tonight.

语病在后面一句,“避免.不再发生”,否定的否定,为肯定,就是还要发生.

距离 ÷ 速度= 4.2 x 9.46x10^12 x10³ / (10^5 x 60 x 60 x 24 x 365.2425) ≈ 12600 年
或
光速 ÷ 船速 x 4.2 = 3x10^9 / 10^5 x4.2 = 12600 年

水星是距离太阳最近的行星,其次是金星,然后才是地球,由于冥王星已经被国际天文联合会排除在行星之列,所以目前距离太阳最远的行星是海王星,它距离太阳的平均距离大约是45亿千米

做功,力和位移必须是同一直线,当不是同一直线时,需要进行分解.可以根据力的方向找位移,也可以根据位移的方向找力. 如一个物体被一个绳子栓住,另一端链接在定滑轮上.为何位移是绳子的长短变化,而不是物体沿地面移动的...

就是说只有这个选择,幽默的自我嘲笑下而已
=.=意思就是：我是看书吧,还是看书吧,只好看书了.

因为之路的灯泡短接后,依然有干路上的灯泡保护,所以不会短路

到《读者》《青年文摘》《意林》去找,关键平时多积累,写作文时肯定能用的到!

因为“刀补加入后,不能有连续两段或以上的非工作平面内的轴移动指令”但是,通常我们在宏程序中世这样的：建立刀补-----加工-------取消刀补-------计算------判断然后返回或是继续下面的程序段,这中间已经好几段了,所以会报警!一般我们是通过改某个变量来调整的,比如用宏程序加工椭圆,我们只是改变下半径就可以到达我们的目的了!同理其他的也可以这样!

∵ABCD为平行四边形
AB∥CF
∠BAE=∠EFC
∠ABE=∠CEF
E为BC中点
BE=EC
△ABE≌△FEC（AAS）
2：∠AEC为△ABE外角
∠AEC=∠ABE+∠BAE
∵∠AEC=2∠ABE
∴∠ABE=∠BAE
AE=BE∵BE=CE
∵全等
∴AE=EF
即AE=BE=FE=CE,∴四边形为矩形

In recent years, parents have to make such hard decision on how much time should their children spend on watching TV, playing computer games as well as surfing on the Internet.
Some advertisement announce that they can help obese person lose weight without doing any exercise and being on a diet while others claim that thier medicine can cure cancer and AIDS.

设问 例如 Have you ever seen someone ...(一些有个性的行为包括语言穿着做法等) ---问2-3个问题 来引出后文
或者写一个名人名言 当然 不一样非得是名人说的 可以自己编一个 比如说 "There are no two poeple in this world the same"之类的来引题
或者说一个现象 例如说There is a heated discussion about.recently
当然也可以举一个相关的新闻报道或者故事 A news report or a story I read recently about.

跟全球变冷有关系,这是一个周期性的气温变化
20世纪70年代初出现的气候“变冷说”一度成为主流.1971年丹斯加德等人发表的格陵兰冰芯氧同位素谱分析成果表明,地球气候有10万年轨道周期变化,其中9万年为冷期,1万年为暖期.按此规律,目前气候的暖期已接近尾声.日本气象厅朝仓正1973年撰文预言,地球将于21世纪进入“全球变冷”.美国威斯康辛大学环境研究所布莱森认为,地球目前正在非常缓慢地进入另一个大冰河期.当时的“变暖说”以大气热污染为依据,其理论现在成为主流.
全球变冷是气候发展趋势20世纪70年代,在美国布朗大学专门召开的一次“当前的间冰期何时结束和如何结束”研讨会上,学者们举出实例证明地球气温已经在开始下降.他们表示从暖到冷的变化可以不足500年,如果人类不加以干涉,当前的暖期将会较快结束,全球变冷以及相应的环境变迁就会随之来临.会议的两位发起者甚至还向当时的美国总统尼克松写信发出警报.这种“冰期将临”的观点一直持续了20年.
2008年,俄罗斯科学家哈比布罗·阿布萨马托夫持提出,地球在1998年到2005年度过了全球变暖的高峰期,全球变暖主要是太阳几乎在整个20世纪持续保持不寻常的高发光度造成的,现在太阳的发光强度正在逐渐下降,大约在2041年会降到最低点,正是这一点将成为地球显著变冷的原因,但海洋会推迟地球显著变冷的过程,全球变冷的高峰期将出现在2055年到2060年.哈比布罗·阿布萨马托夫现就职于俄科学院天文台,从事宇宙实验研究工作,主要对太阳进行观测研究.他认为全球变冷的主要原因是太阳活性发生变化.全球变暖将逐渐停止,即使大气二氧化碳浓度增长了4%.

活泼金属氧化物,氢化物,过氧化物,氮化物,碳化物,强碱和绝大多数盐都是离子化合物.其他都是共价的

But I found that even in casual way of writing and the littering behavior on campus. And recently it has become more and more serious. I think this type of behavior is very bad, must not let this behavior continues to exist in the campus. Should adopt effective measures to stop this behavior, and guide for campus behavior. First of all, that this kind of behavior is forbidden. And in the radio again this behavior is bad, to persuade students not to hurt the campus behavior, you should learn to love our campus. Second, let the students clean the campus, keep the campus clean. Finally, to supervise the behavior. Once found someone to hurt the campus behavior, will make criticism and guidance to the people, and let other students take this as a warning. Above, is my view and advice. The hope is to help our campus, to make our campus more clean and beautiful. Thank you for reading. Wish you success in your work, a happy mood.

实验合理,对照实验的要求,不错

相关定理与切线有关的定理垂直于过切点的半径；经过半径的外端点,并且垂直于这条半径的直线,是这个圆的切线.切线的判定方法：经过半径外端并且垂直于这条半径的直线是圆的切线.切线的性质：（1）经过切点垂直...

Chinese people's liberation arm work around the clock to protect us,in flood 1998,snowstorm in sorth,and earthquake in Wenchuan,they give us more than sweat and youth,sometimes even life will be sacrificed.

令P(x,1/2x^2)为抛物线上的点,显然x∈R
由两点间距离公式有PA^2=(x-6)^2+(1/4)x^4
令PA^2=f(x)=(x-6)^2+(1/4)x^4
易知f'(x)=2(x-6)+x^3
=x^3+2x-12
=(x^3-8)+2(x-2)
=(x-2)(x^2+2x+4)+2(x-2)
=(x-2)(x^2+2x+6)
令f'(x)=0,即(x-2)(x^2+2x+6)=0
因x^2+2x+6>0恒成立（判别式判断）
则x-2=0,即x=2
显然当x0,此时f(x)递增
表明x=2处f(x)取得最小值
即f(x)min=f(2)=20
即(PA^2)min=20
所以PAmin=2√5
此时P点坐标为(2,2)

可以肯定的是到现今为止还没有确凿的证据证明地球曾有外星人来访过.有些人把现今科学不能解释的自然现象说成是外星人来访(ufo)是很常有的事.而且很多时候他们看到的其实是人工飞行器.又有些人把人类的古文明说成是外星文明,把现在解释不了的东西都归功为外星人杰作,这是对人类本身的侮辱!其实人的创造力是很强的,我们现在不能做到的事情不代表古代人类就做不了.不要什么都说是外星人.而UFO是指不明飞行物体,泛指所有非人造飞行物.UFO肯定是有的,人类不能解释的东西多着呢.但是否与外星人有关就不得而知.

tan^2+1=sin^2/cos^2+1=(sin^2+cos^2)/cos^2=1/cos^2
开方后得到±1/cos,再讨论cos的正负就行了.

有歧义
这个句子有两个意思
1,他父亲考察工作最近去过云南（时间上的最近,几天以内）
2,他父亲考察工作最近去过云南（距离上的,表示他父亲经常考察工作,最近的是云南,在其他地方都要比云南远）

1. Definition （定义）
定语从句: 在复合句中,修饰某个名词或代词的从句叫定语从句.
被修饰的词称为先行词(antecedent )．
连接定语从句和先行词的词称为关系词.
2. 关系词：
关系代词(relative pronoun):
who,that ,which, whom,whose 作主语／宾语 / 定语
关系副词(relative adverb): when, where ,why 作状语
3. 关系词的作用
1）连接作用
2）替代作用
3）成分作用
Madame Curie is unforgettable because she is the first female who /that won the Nobel Prize.
4.关系词的选用
关系词的选用是依据先行词在定语从句中的所充当的成分来确定的.
Madame Curie is unforgettable because she is the first female who /that won the Nobel Prize.
Madame Curie is unforgettable because she is a scientist whose discoveries are very important
Madame Curie is unforgettable because she is a scientist whom/that we can learn much from.

Things / places
The Internet is unforgettable because it is a thing that/which has greatly changed our way of life.
The Internet is unforgettable because it is a necessity which /that modern life can’t go without.
The Internet is unforgettable because it is a thing whose functions (功能)are powerful.
5. 在下列情况关系代词只能用that而不用which.
先行词为all, everything, anything, nothing, none, little,few, much等不定代词时.
eg. You must do everything that I do.
2) 先行词被all, every, no, any, little, much, some, just等修饰时.
eg. Is there any question that troubles you much ?
3) 当先行词被序数词或形容词最高级以及the only, the very, the last等修饰时.
eg. James is the best singer that I have ever known.
4) 当先行词是人和物构成的词组时.
eg. They were talking about the people and places
( that ) they had visited.
5) 当句中有who 或which 时,为避免重复.
eg. Which is the book ( that ) he borrowed from the library ?
eg. Who is the person that is talking to our headmaster?
6). 关系代词在从句中作表语时;
eg.My hometown is no longer the village that it used to be.
由关系副词引导的定语从句
关系副词在定语从句中相当于一个介词词组,通常在定语从句中是充当状语的,表示地点、时间或原因状语.
1. Where： 当先行词是表示地点的名词,且从句中缺少地点状语,此时使用where.
The hotel where we stayed wasn’t very clean. in the hotel in which
2. When: 当先行词是表示时间的名词,且从句中缺少时间状语,此时用when.
Do you remember the day when we met? on the day on which Morning is the best time when we practise reading
English aloud. in the morning in which
3.Why: 当先行词是reason,且从句中缺少原因状语,
此时用why 做关系词.
Can you tell me the reason why the little boy cried?for the reason for which
where/when/why= prep.+which
4.在“介词+关系代词”引导的定语句中, 介词在定语句中的位置一般有两种：1). 一些介词既可以放在关系代词的前面,也可以放在从句中.如：
I paid 2 dallors for the pen.
The pen which I paid 2 dollars for was lost.
= The pen for which I paid 2 dollars was lost.
The lady whom he was dancing with stepped on his foot.
= The lady with whom he was dancing stepped on his foot.
2). 在含有介词的动词短语中,介词一般不提前,如：
This is the very boy whom I have been looking for.
The old lady who needs to be taken care of has no children.
直接放在介词后面,不用that .
先行词指人时介词后用whom, 指物用which.
5. 在“介词+关系代词”引导的定语句中,介词的选择一般采取以下几种方式：
1).根据先行词选择介词,如：
I still remember the day on which she first wore that pink dress
The pencil with which I wrote my homework was broken.
(句中介词with是根据先行词pencil来的.
with the pencil表示“用铅笔写”, 是固定搭配.)
2).根据从句中动词选择介词,如：
The girl about whom I talked with you yesterday will come to our school soon.
(句中介词about是根据词组talk about 来的.)
The hotel at which you stayed last year is being rebuilt now.
(stay at some places)
3).根据句意选择介词,如：
The brave man by whom the tiger was shot is a good hunter.
The clever boy made a hole in the wall, through which he could see what
定语从句的分类：
限制性定语从句和非限制性的定语从句
限制性定语从句不用逗号与主句分开,对所修饰的词起特指或限定的作用,去掉后意思不完整或不太清楚.翻译成中文时,一般把定语从句翻译在先行词之前.
引导限制性定语从句的关系代词有who, whom, whose, that, which, of which和关系副词when, where, why等.
eg. This is the man who helped me.
I was the only person in our office that was invite to the palace ball.
非限制性的定语从句和主句之间往往用逗号分开,只对被修饰的词语或主句起补充说明的作用,去掉后对句意影响不大.翻译时通常把定语从句翻译在先行词后边,作为附加说明.
引导非限制性定语从句的关系代词有who,whom, whose, which, as和关系副词when, where,一般不用that 引导.
eg. I have two sisters, who are both doctors.
Last Sunday they reached Shanghai, where a meeting was holding.
定语从句的考查热点
1.间隔式定语从句
定语从句一般紧跟在先行词之后,但定语从句先
行词之间有时会插入别的成分,构成先行词与定
语从句的隔离.
eg. This is the article written by him that I spoke to you about.
He was the only person in this country that was invited.
(1). 因定语从句过长,为使句子保持平衡,通常定语从句和其所修饰的名词或代词分开.
eg. The film brought the hours back to me when I was taken good care of in that faraway villiage.
(2). 在定语从句中使用“插入语”以增加句子的灵活性.
eg. Kate was always speaking highly of her role in the play, which, of course, made the others unhappy.
The pen I thought I had lost is on my desk, right under my nose.
2.定语从句中的谓语动词与先行词保持一致.
当引导定语从句的关系代词在从句中做主语时,定
语从句的谓语动词的数的形式应与先行词保持一致.
eg. I, who am your classmate, will try my best to help you.
He, who is your classmate, will try his best to help you.
注意句式：
one of + 复数名词+关系代词+复数动词
the (only/very) one of +复数名词+关系代词+单数动词
He is one of the students who have made great progress.
Tom is the only one of my friends who has been abroad.
Where引导的地点状语从句与定语从句的区别:
1.Where there is a river, there is a city.= In the place where there is a river, there is a city.
2. You should make it a rule to leave things where you can find them again.
= You should make it a rule to leave things in the place where you can find them again.
3. Go (to the place) where you like to go.
当where 引导的地点状语从时, 可换成含有定语从句
where 引导的从句 ,等于 in /to/ at the place where

比如力是一个矢量,他有一个固定的作用点,也就是固定的矢量,如果没有那个固定的点的就是滑动矢量.比如在直角三角形内,只是固定直角,而滑动斜边的话,则两直角边的长短可以任意调节,斜边也就是一个滑动矢量,或在坐标系内,比如第一象限内,有一条线段两端点分别在X、Y轴上,可以任意滑动,就构成一个滑动矢量.

A,成直线是日（偏）食或月食,看不到月亮,错了
B,这种事万年难遇,当然不是一年一次,错
C,同一天体引力跟距离平方成反比,应该是2.25倍,错
D,就算你忘了这个复杂的公式,但也只剩这个能对了吧~

解题思路：此题考查的是人类的起源问题，据此答题．

A、老鼠的器官可作为人体器官移植的来源是错误的，首先从体型大小不合适，另外异种器官移植培养出的器官移植于人体，会存在跨物种病毒感染的隐患等问题．故错误；
B、人类可能起源于古代类人猿，而不是古代的鼠类，故错误；
C、老鼠的基因有9 8%～99%与人的相同，我们可以可在老鼠体内做某些人体病理实验，故正确；
D、克隆应在同种物种之间进行，所以在猴子体内植入老鼠克隆胚胎是错误的，故错误．
故选C

点评：
本题考点： 人类与动物的关系．

考点点评： 关于人类的起源问题，在中考中考查内容不多，而且难度不大．

exponent:是数学上的指数,例如2的3次方,3就是指数.
index:是指价格、股票等方面的比较指数.
两者不能混用.

太阳系内,除月球外,离我们最近的天体是金星.
金星与地球的公转轨道相邻,与地球平均的距离为4100万公里,但人类还没能登上金星.但人类发射的探测器已经多次登陆金星.
1965年11月5日,苏联发射的探测器金星3号,在金星表面进行了硬着陆并全部摔毁,这是人类的探测器第一次降落在金星上.
除此之外,人类的探测器还曾着陆过火星.

R2-R1错误.这时R1已经变化了.

最近在看《千亿个太阳》里面对太阳聚变启动的原因归结为隧道效应?认为太阳的温度不足以启动聚变,是这样的吗?是这样.另外,为什么电子不会坠入原子核?所有天体之所以没有坠入一点,是因为互相引力平衡吗?电子这种微观世界不了解,只说天体.人造卫星之所以绕地球转,而没有全坠到地球上,是因为它绕地球转的速度够快.同样,地球没有坠到太阳上,也是这个道理.不客气.

24k金常被人们认为是纯金,但实际含金量为 99.98%.黄金及其制品的纯度叫作“成色”

我家养过螳螂,球鼠妇,鱼,螺蛳,水蜗牛,蜗牛,蚂蚁,鳖龟,蛙,蝉,蚕,虾,猫等等

因为2是鱼类,4是鸟类.而1和3都是哺乳动物

很高兴回答你的问题
选择虎鲸和蝙蝠.
原因如下：
①虎鲸属于脊索动物门,哺乳纲,
②鳗鱼属于脊索动物门,鱼纲；
③蝙蝠属于脊索动物门,哺乳纲；
④鹰属于脊索动物门,鸟纲,
因为界、门、纲中纲是最小的,
虎鲸和蝙蝠同纲,因此它们的亲缘关系相对最近.