问题 选择题

在大海上想要获得淡水,可采用图示的“充气式太阳能蒸馏器”。它是通过太阳照射充气物内的海水,产生大量水蒸气,水蒸气在透明罩内壁形成水珠,收集即可。这个过程中发生的物态变化是:

[ ]

A.先蒸发,后沸腾

B.先熔化,后凝固

C.先升华,后凝华

D.先汽化,后液化

答案

答案:D

题目分析:

海水是液态的,水蒸气是气态的,液态变为气态的现象叫汽化;水蒸气在透明罩内壁形成水珠,气态又变为了液态的现象叫液化.
故选D.

阅读理解

“Why does the chicken cross the road? To get to the other side!”

That’s an old joke in the west, but it came to my mind again when I saw people crossing the road at the intersection of Shanxi Road and Huaihai Road in Shanghai.

When the traffic light was red, a group of people were waiting for the light to change. Suddenly one man began rushing to the other side of the road. Soon others followed him at the crossing and more people did the same. Just like chickens, they didn’t mind the honking horns(喇叭声) and kept crossing the road in a mess.

Every year several thousand people are either killed or hurt on the roads in Shanghai. And at least one third of them were jaywalking(乱穿马路). Jaywalking is very common in Shanghai. It seems that jaywalkers are not afraid of the danger to themselves.

Traffic laws are to keep people safe. So we should obey them, and have good road-crossing habits. When someone starts to jaywalk, we should stop him, and never follow him. That way we can avoid the traffic accidents.

小题1:The underlined word “intersection” here probably means “       ”.

A.road

B.bridge

C.crossing

D.traffic小题2:The writer saw people      in Shanghai that day.

A.crossing the road in a mess

B.waiting for the green light patiently

C.crossing the road with chickens

D.hurting each other in the street小题3:How does the writer like what he saw in Shanghai that day?

A.He thinks it’s OK.

B.He thinks it’s wrong.

C.He has no idea of it.

D.He doesn’t mention it

单项选择题