问题 问答题 简答题

如何防止药物的自动氧化?

答案

参考答案:

防止药物自动氧化的措施如下:

(1)注意密闭保存,保持药物处于干燥状态,必要时做成水溶液。

(2)避免或减少与氧接触,如充人惰性气体或药物充满容器并密闭。

(3)有些药物在光照催化下易自动氧化,故应避光储存。

(4)调节适当的酸碱度。

(5)避免引入金属离子或添加络合剂。

(6)添加适当的抗氧剂。

(7)受热易氧化的药物宜置阴凉处存放;选择适当的消毒灭菌温度,控制加热时间。

(8)改变化学结构,制成稳定的衍生物。

单项选择题
阅读理解

Three boys, Tom, Sam and Jim bought seventeen apples. Tom wanted the half (一半). Sam wanted one-third (三分之一),and Jim wanted one-ninth (九分之一)• But they didn’t know how to do.

Just at that time,a little boy came with an apple in his hand. The boy said to them, “Don’t worry. Let me help you” Then he put his apple into their apples, and made the number of the apples eighteen. Then he gave Tom nine apples, he gave Sam six apples,and he gave Jim two apples. He gave away seventeen apples and took his apple back.

The three boys were very happy. And they said: “How clever the boy is!”

根据短文内容,选择正确的选项。

小题1:There were___apples when the three boys divided(分配)them.

A.fifteen

B.sixteen

C.seventeen

D.eighteen小题2:What was the three boys' problem?

A.They couldn’t eat the apples.

B.They couldn’t go home.

C.They couldn’t divide the apples.

D.They wanted to borrow some apples,小题3:What did the little boy do to help them?

A. He put his apple into theirs when he divided the apples.

B. He kept an apple to divide the apples.

C. He got one apple from another man.

D. He ate an apple before he divided them.小题4:Which one is right?

A. The three boys asked the little boy to divide their apples.

B. The little boy told them how to divide their apples.

C. The little boy wanted to help them.

D. The little boy wanted to take away their apples.小题5:The underlined sentence “How clever the boy is!” means   in Chinese.

A.这个男孩是多么地感激啊!

B.他怎么样才能聪明啊!

C.这是一个什么样的男孩啊!

D.多么聪明的男孩啊!