问题 选择题

在常温下,pH都等于5的CH3COOH和NH4Cl两种溶液,由水电离产生的c(H+)前者和后者的关系正确的是(  )

A.大于

B.等于

C.小于

D.无法确定

答案

醋酸是弱酸,电离出氢离子而抑制水电离,氯化铵为强酸弱碱盐,铵根离子水解而促进水电离,所以由水电离产生的c(H+)前者小于后者,故选C.

阅读理解

Philip was a nine-year-old boy in a Sunday school class of 8-year-old girls and boys. Sometimes the third graders didn’t welcome Philip into their group and usually tricked him. This was not because he was older, but because he was “different”. You see, Philip suffered from a condition called Downs’s Syndrome. This made him “different”, with his facial characteristics, slow responses and mental problems.

One Sunday after Easter, the Sunday school teacher gathered some plastic eggs that pulled apart in the middle. The teacher gave one to each child. On that beautiful spring day, the children were to go out and discover for themselves some symbol of “new life” and place it inside the plastic eggs.

After the children returned to the classroom, the teacher opened their eggs one by one, asking each child to explain that symbol of “new life”. The first opened egg contained a flower. Everyone cheered. In another was a butterfly…. When the teacher opened the last egg, it was empty. “That’s stupid,” said someone. The teacher felt a pull at his shirt. It was Philip. Looking up, Philip said, “It’s mine. I did it. It’s empty. I have new life, because the tomb is empty.” Not a sound was heard in class at all. From that day on, Philip became a real part of the group. They welcomed him, and whatever made him different was never mentioned again.

Philip’s family knew he wouldn’t live a long life, for there were too many things wrong with him.

小题1:The underlined word “condition” in the first paragraph probably means ________.

A.grade

B.status

C.health

D.disease小题2:It can be inferred from the first paragraph that ________.

A.The 8-year-olds were sometimes cruel

B.The 8-year-olds were friendly to Philip

C.Philip was really different in school

D.Philip was older and more sensitive小题3:The teacher gave each child one plastic egg to let them ________.

A.play around on that beautiful spring day

B.put some symbol of “new life” into it

C.try to pull it apart in the middle

D.go out and discover themselves小题4:After Philip explained his new life, ________.

A.The class thought he was clever.

B.The class fell silent.

C.He began to study in the class.

D.He felt dying.小题5:We learn from the passage that ________.

A.The teacher used to have classes outdoors

B.The Philip’s new life wish was empty

C.Philip was healthy as a whole

D.Philip was accepted by his classmates in the end

判断题