薄板咬缝的结构形式有（）扣、（）扣、（）扣、（）扣、（）扣。

（10分）质量为M的楔形物块上有圆弧轨道，静止在水平面上。质量为m的小球以速度v₁向物块运动。不计一切摩擦，圆弧小于90°且足够长。求小球能上升到的最大高度H和物块的最终速度v。

已知2A（g）+B（g）⇌2C（g），△H=-akJ/mol（a＞0），在一个有催化剂的固定容积的容器中加入2mol A和1mol B，在500℃时充分反应达平衡后C的浓度为ωmol/L，放出热量为bkJ．

（1）比较a______b（填“＞”“=”或“＜”）．

（2）下表为不同温度下该反应的平衡常数．由此可推知，表中T₁______T₂（填“＞”、“=”或“＜”）．

T/K	T1	T2	T3
K	1.00×107	2.45×105	1.88×103

若在原来的容器中，只加入2mol C，500℃时充分反应达平衡后，吸收热量为ckJ，C的浓度______（填“＞”“=”或“＜”）ω mol/L，a、b、c之间满足何种关系______（用代数式表示）．

（3）在相同条件下要想得到2akJ热量，加入各物质的物质的量可能是______．

A.4mol A和2mol B B.4mol A、2mol B和2mol C

C.4mol A和4mol B D.6mol A和4mol B

（4）为使该反应的反应速率增大，且平衡向正反应方向移动的是______．

A．及时分离出C气体 B．适当升高温度

C．增大B的浓度 D．选择高效催化剂

（5）若将上述容器改为恒压容器（反应前体积相同），起始时加入2mol A和1mol B，500℃时充分反应达平衡后，放出热量为dkJ，则d______b（填“＞”、“=”或“＜”），理由是______．

（6）在一定温度下，向一个容积可变的容器中，通入3molA和2molB及固体催化剂，使之反应，平衡时容器内气体物质的量为起始时的90%．保持同一反应温度，在相同容器中，将起始物质的量改为4mol A、3mol B和2mol C，则平衡时A的百分含量______（填“不变”、“变大”、“变小”或“无法确定”）．

我国各民族分布特点是[ ]

A．各民族杂居在一起      

B．大杂居，小聚居

C．小杂居，大聚集        

D．各民族独居

阅读理解。

     Grammarphobia is the fear of grammar. This fear attacks almost everybody at one time or

another, and it's most likely to strike during English or language arts classes. Even people who

love reading and writing have been known to get feverish and insecure when they are aware

of the possibility of turning in homework with grammar or spelling mistakes. Though writing

may be enjoyable, being corrected is definitely not!

     Grammarphobes, it's time to put your fears behind you.Grammar isn't that dreadful (可怕的).

Here's why.

     Let's assume you like hearing and telling stories and that you enjoy joking with friends. You

probably also like emailing and instantmessaging.  Well, what do you think makes all these

possible? Grammar!

     Grammar is simply the art of putting words together to make sentences. Whenever you use

words to express yourself, you're using grammar. You do this all the time without even thinking.

     So why think about it? Because good grammar helps you convey the ideas you intend. If your

words aren't right, or if they are not in the right order, the person you are talking to might get the

wrong idea. This can have embarrassing results.

     Grammar helps us understand each other.  It's like a manual (手册) for assembling the words

in your head. You have to put your words together the right way if you want them to make sense.

They can't do what you want if they aren't put together correctly.

     What if everybody you know had a different manual? How would you agree on what others'

words mean? People with different grammar manuals might be speaking different languages.

     Communicating is similar to playing cards.  To make sense, we have to play the same game,

by the same rules. What are the rules for playing the game of English? You already know most of

them without having to open a book.

1. Grammarphobes refer to people who ________. 

A. consider grammar to be boring

B. are worried about grammar homework

C. mind grammar too much in writing

D. are afraid of making grammar mistakes

2. The underlined word "assembling"  in Paragraph 6 may    mean ________.

A. directing                  

B. remembering

C. bringing together        

D. looking for

3. What does playing cards have in common with communicating? 

A. Both need standards.

B. Both can be interesting games.

C. Both can be learned easily.

D. Both can make sense for our life.

4. What might be the main idea of the passage?  

A. Forgetting grammar when writing.

B. Grammar is not horrible.

C. Improving grammar through writing.

D. What is grammarphobia?

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