海水不得用于拌制钢筋混凝土和预应力混凝土，主要是因为海水中含有大量盐，( )。A．(

关于产妇产褥期的临床表现，下列哪项是正确的（）

A.分娩后经过数小时，可见子宫底稍下降

B.产妇于产后一周内脉搏增快

C.产后宫缩痛多见初产妇

D.子宫复旧需2～3周

E.子宫复旧速度因母乳喂养而加速

阅读理解。

     "Dr. Papaderos, what is the meaning of life?"

     The usual laughter followed, and people stirred to go. Papaderos held up his hand and stilled the

room and looked at me for a long time, asking with his eyes if I was serious and seeing from my eyes

that I was.

     "I will answer your question."

     Taking his wallet out of his hip pocket, he fished into a leather billfold and brought out a very small

round mirror, about the size of a quarter. And what he said went like this:

     "When I was a small child, during the war, we were very poor and we lived in a remote village. One

day, on the road, I found the broken pieces of a mirror. A German motorcycle had been wrecked in that

place.

     I tried to find all the pieces and put them together, but it was not possible, so I kept only the largest

piece. This one, and, by scratching it on a stone, I made it round. I began to play with it as a toy and

became fascinated by the fact that I could reflect light into dark places where the sun would never

shine-in deep holes and crevices (裂缝) and dark closets. It became a game for me to get light into the

most inaccessible places I could find.

     I kept the little mirror, and, as I went about my growing up, I would take it out in idle moments and

continue the challenge of the game. As I became a man, I grew to understand that this was not just a

child's game but a metaphor for what I might do with my life. I came to understand that I am not the

light or the source of light. But light-truth, understanding, knowledge-is there, and it will shine in many

dark places only if I reflect it.

     I am a fragment (碎片) of a mirror whose whole design and shape I do not know. Nevertheless,

with what I have I can reflect light into the dark places of this world-into the black places in the hearts

of men-and change some things in some people. Perhaps others may see and do likewise. This is what

I am about. This is the meaning of my life."

1. On hearing the author's question, Dr. Papaderos _____ at first.

A. laughed at his foolishness     

B. wasn't sure of the answer

C. doubted his seriousness        

D. wasn't interested at all

2. Why did Dr. Papaderos like the small round mirror so much as a child?

A. Because he was too poor to afford other toys. 

B. Because it could shine the places where the sun couldn't reach. 

C. Because he believed it would bring good luck to him. 

D. Because it told him a lot about what life really meant to him.

3.  The underlined "metaphor" in the 7th paragraph most probably means _____.  

A. symbol      

B. source         

C. light    

D. purpose

4. Which of the following might be the best title for the passage?

A. A Special Game in the Childhood    

B. A Broken Piece of Mirror

C. Dr. Papaderos' Experience    

D. The Meaning of Life

若A为n阶矩阵，且A³=0，则矩阵(E-A)^-1=( )．

A．E-A+A²

B．E+A+A²

C．E+A-A²

D．E-A-A²

生产有毒有害化学产品过程中，符合安全的操作要求是（）。

A.开灯取暖

B.带电作业

C.无盖存放

D.穿戴工作服

小于1000立方米的储气罐与明火、散发火花地点的防火间距为（）m。

A.20

B.30

C.10