问题 选择题

.化学反应经常伴随着颜色变化,下列有关反应显示的颜色正确的有(   )

①氢氧化亚铁在空气中最终变为灰绿色;

②淀粉溶液遇单质碘变为蓝色;

③向硫酸铁溶液中加入KSCN溶液变为红色;

④新制氯水久置后变为无色;

⑤无水硫酸铜吸收水蒸气变成浅绿色;

⑥品红溶液通入过量二氧化硫后褪色。

A.2个

B.3个

C.4个

D.5个

答案

答案:C

①氢氧化亚铁在空气中最终变为红褐色;②淀粉溶液遇单质碘变为蓝色;③向硫酸铁溶液中加入KSCN溶液变为红色;④新制氯水久置后变为盐酸,颜色为无色;⑤无水硫酸铜吸收水蒸气变成蓝色;⑥品红溶液通入过量二氧化硫后褪色,故选C项

阅读理解

When I was in medical college, I went camping with some of my friends. The season was summer; therefore, we chose to go to the seaside. After arriving there, we rent a room and left our luggage there. We finished lunch and then decided to rent a boat because the sea and the weather were beautiful.

We started to row, but about one mile out, the weather suddenly changed. Although the weather was not good, we didn't want to give up, but finally my friends and I agreed that we should go back. We tried to change the boat's direction, but as soon as we changed it, the oarlock (桨架)broke. Therefore, we were unable to turn back. We had to wait for help because we couldn't do anything.

After seeing the change of weather, we shouldn't have continued to row, but it was too late. We regretted(后悔) it. The sea changed a lot, the waves got very high, and the boat began to shake like a cradle(摇篮). One of my friends started to cry; another started to vomit(呕吐). Three hours passed, and nobody came to help us. We were just praying.

Fortunately, after five long hours of waiting, two big boats came to rescue us and we escaped. If they hadn't come to get us, we would have crossed the border between Turkey and Greece because the border was very close.

This story is the most exciting story of my life because we could have died, but luck was with us and we escaped.

小题1:What does the author mainly tell us in this passage?

A.An experience at sea.

B.An exciting experience when swimming.

C.The changeable weather at the seaside.

D.It is dangerous to boat at sea.小题2:When did they begin to go boating in the sea?

A.In the morning.

B.In the afternoon.

C.In the evening.

D.At night.小题3:What they regretted was that ______ when the weather changed.

A.they went camping at the seaside

B.they went on rowing

C.the waves got very high

D.they started too late小题4:One of his friends started to vomit because _________.

A.he came down with a disease

B.they stayed three hours at sea

C.the boat shook too much

D.nobody came to help them

单项选择题