问题 选择题

如图表示水溶液中c(H)和c(OH)的关系,下列说法正确的是

A.ab线上任意点溶液均显中性

B.b点时,溶液的pH=6,显酸性

C.图中温度T1>T2

D.在水中通入适量HCl气体可从a点变到c点

答案

答案:A

题目分析:A、根据图像可知ab线上任意点c(H)=c(OH),因此溶液均显中性,A正确;B、b点时,溶液的pH=6,但溶液中c(H)=c(OH),因此溶液显中性,B不正确;C、水的电离吸热,加热促进电离,而溶液中b水的离子积常数大于a点水的离子积常数,因此图中温度T1<T2,C不正确;D、在水中通入适量HCl气体抑制水的电离,但水的离子积常数不变,因此不可能从a点变到c点,D不正确,答案选A。

完形填空

四.动词的适当形式填空

open the floor, have a lasting effect on, cut back on, think of…as, flow into, what if, wipe out, take responsibility for, result in, in the form of, under way, focus on, rely on

1.The pollution ____________________ unsafe drinking water which has led to health problems for people living near the river.

2.Pollution is very bad for the people who _________________ the river for water.

3.Two special government projects are also ________________ to protect the river.

4.The projects _________________ problems along the Yangtze River such as water conservation.

5.There’s also another resource in the fight against desertification, ___________________ the China National Desertification Monitoring Centre.

6.______________ we run out of space?

7.People should ______________________________ not buying certain kinds of fish, because there are not many left in the ocean.

8.Now we _____________________ for discussion.

9.Many types of waste ________________ our water.

10.In addition, many sea creatures __________________________ by fishing boats.

11.These boats catch large numbers of fish without giving them time to lay eggs. This ________________________________ the number of fish left for us to eat.

12.My suggestion is that we should try to ___________________ production and reduce the amount of things we make and buy.

13.The people running these factories are very concerned about the environment. We need to stop ________________ companies and money _______ the enemy.

选择题