问题 选择题

近年来,乳酸(化学式为C3H6O3)成为人们研究的热点之一。乳酸在医药、食品等工业中应用前景广阔。人在剧烈运动后,血液中会产生较多的乳酸,使肌肉酸痛。放松一段时间后,由于乳酸与吸入的氧气反应生成二氧化碳和水,使肌肉的酸痛感消失。下列有关乳酸的叙述中,完全正确的是[ ]

A. 乳酸中碳、氢、氧三种元素的质量比为1:2:1

B. 乳酸属于有机物,它是由3个碳原子、6个氢原子和3个氧原子构成

C. 乳酸是一种氧化物,每个分子中共有12个原子核

D. 乳酸与氧气反应的化学方程式为:C3H6O3+3O2=3CO2+3H2O

答案

答案:D

阅读理解

Little Robby, our neighbour’s nephew, carefully drew some water into a bowl and started for the door. How I hated this water rationing (定量供应). We were forced to bathe in the deep little pond we shared with Jessie, our cow. Wells were dry, and crops transformed to dust.

I watched Robby sitting down onto the steps to my house. Bees buzzed circling his hair, and he buzzed with them. I remembered his aunt’s words: I don’t know what I was thinking when I took him in. The crash killed my sister, and he wasn’t hurt, but he can’t talk. He’s in a world of all his own.

Why couldn’t she see the wonderful gifts this boy possessed? He was blessed with a loving nature and a deep admiration for all living things, and I knew he could talk to animals. My heart ached for Robby, who was to stay with us for the summer, and had already been the dearest part of our world, eagerly tending the garden with me and my husband, Tom.

On a string around Robby’s neck hung a whistle, in case he was ever lost or in danger. After all, he could not call out for help. But he knew perfectly well that the whistle was not a toy. Blowing on it would bring us both running. I had told him the story of the boy who cried wolf, and I knew he understood me.

I sighed as I cleared up the last supper dish. Every ounce of recycled water was saved for a tiny vegetable garden Robby had planted. Tom turned to me. “You know, honey, I’ve been thinking about...”

Before he could continue, a scream from the yard made us jump. My God! It’s Robby’s whistle! When we reached him, he was pointing excitedly to the sky. Looking up, we saw the most magnificent sight: Rain Clouds! “Robby! Quick! We need all the pots and pans!”

Robby raced with me to the house. A drop of water fell on my pot and then another. Soon the yard was enveloped in soaking, glorious rain. We all stood with faces held upward to feel the comfort of it. Tom picked up Robby and danced about the pots, shouting and whooping, “Rain for Robby!” Tom swung about to show me Robby’s face: he was laughing right out loud, “W-W-Wobby’s!” “Wobby’s … wain … Mom,” giggling(咯咯地笑), and stretching out one tiny hand in the shape of a cup to catch the rain.

I hugged them both, tears of joy mixing with the rain.

小题1:The underlined phrase “the wonderful gifts” in the 3rd paragraph refers to Robby’s ______.

A.love for nature and all living things

B.kindness to help others around

C.independence since his childhood

D.readiness to accept what happened to him小题2:It was because ______ that the author and her husband would run on hearing the whistle.

A.it was going to rain

B.Robby often surprised us with his whistle

C.something bad might happen to Robby.

D.Robby might find something special小题3:What can we learn from the passage?

A.Robby was old enough, but still couldn’t speak.

B.Robby’s aunt regretted bringing Robby home.

C.Robby didn’t accept the author and Tom as his parents.

D.Robby happened to find the rain cloud and was terrified.小题4:It can be concluded from the passage that ______.

A.we should show mercy for the disabled children

B.every child has his own talent however young he is

C.children from poor families take responsibilities earlier

D.children’s sensitive hearts are worthy to be taken care of

单项选择题