下列为化学配伍变化的是 （ ） A．药粉结块 B．液化 C．发生爆炸 D．潮解

难度与区分度的关系，一般来说，较难的项目对高水平的受测者区分度（），中等难度的项目对中等水平的受测者区分度高。

A.中等

B.一般

C.高

D.低

阅读理解

     When I was growing up, I was embarrassed to be seen with my father. He was severely crippled and

very short, and when we would walk together, his hand on my arm for balance, people would stare. If he

ever noticed or was bothered, he never let on.

     It was difficult to coordinate(协调) our steps - his slow, mine impatient -- and because of that, we didn't say much as we went along. But as we started out, he always said, "You set the pace. I will try to

adjust to you. "

     He never talked about himself as an object of pity, nor did he show any envy of the more fortunate or

able. What he looked for in others was a "good heart", and if he found one, the owner was good enough

for him.

      Now that I am older, I believe that is a proper standard by which to judge people, even though I still

don' t know accurately(精确地) what a "good heart" is. But I know the times I don't have one myself.

     Unable to engage in many activities, my father still tried to participate in some way.

     I now know he participated in some things indirectly through me, his only son. When I played ball

(poorly), he "played" too. When I joined the Navy, he "joined" too. And when I came home on leave, he

saw to it that(务必保证、一定) I visited his office. Introducing me, he was really saying, "This is my son, but it is also me, and I could have done this, too, if things had been different." Those words were never

said aloud.

     He has been gone many years now, but I think of him often. I wonder if he sensed my unwillingness

to be seen with him during our walks. If he did, I am sorry I never told him how sorry I was, how

unworthy I was, how I regretted it. I think of him when I complain about small affairs, when I am envious

of another's good fortune, when I don't have a "good heart".

     At such times I put my hand on his arm to regain my balance, and say, "You set the pace, I will try to

adjust to you."

1. The author felt unhappy walking with his father because __________.

A. he was pitiful for his father's physical disability

B. it was hard for them to walk at the same pace

C. he didn't want others to know he had an ugly father

D. it was not easy for his father to keep balance

2. In the father's view, the most important quality a good person should have is __________.

A. beautiful appearance

B. excellent health

C. a smart head

D. a good heart

3. It can be inferred from the text that __________.

A. the father was proud of his only son

B. the father took part in all his son's activities

C. the author was upset when asked to his father's office

D. the author was a good ball player and outstanding soldier

4. According to the last paragraph, by saying "You set the pace. I will try to adjust to you.", the

    author means that __________.

A. he is now glad to help his father to walk

B. he regrets his unwillingness to walk with his father

C. he will follow Father's standards of being a good man

D. he will never forget how mentally strong his father was

在神经系统中，______组成中枢神经系统，它作为信息的______，既接受周围的传入信息，又可发出信息到周围．

某研究者调查了某地2005年出生、死亡的资料，欲计算该年的婴儿死亡率，其分母为（）

A.该年婴儿活产总数

B.该年初0岁组人口数

C.该年中0岁组人口数

D.该年末0岁组人口数

E.该年任意时刻0岁组人口数

造成汽缸上、下壁温度差值的原因？