问题 单项选择题

哪种毒物经肝脏代谢后毒性增强

A.磷化锌

B.氰化物

C.阿司匹林

D.对硫磷

E.亚硝酸盐

答案

参考答案:D

解析:毒物被人体吸收后,通过血液分布于全身,主要在肝内<医学全在线>经氧化、还原、水解或结合等作用进行代谢转化。大多数毒物经代谢后毒性降低,这是解毒过程;但也有少数毒物代谢后毒性反而增加,如对硫磷氧化后变为毒性大得多的对氧磷。

阅读理解

 

Hi! I’m Harry. Life used to be kind of difficult for me. The muscles(肌肉) in my arms and legs are weak. I have to be in a wheelchair all day. I can’t use my legs at all, and I’m not too great with my hands. If I drop something it stays dropped until someone picks it up for me. I can’t open doors or switch lights on and off. Carrying everything I need for school is a problem too.

Now things are easier. I have a helping hand. Pete is a golden dog that has been trained to help kids like me. Pete was at dog training school for two years to learn how to do different tasks. I had to be trained too. I had to learn how to give Pete instructions and how to take care of him.

When Pete is working he doesn’t play around. My friends know they are not to pet him or call him when he is working. He can pull my wheelchair and pick up things I drop. Pete carries my books and lunch on his back. He pushes the button on the school lift and opens some kinds of doors. He even knows how to switch lights on.

But best of all, Pete is here when I need a friend.

小题1:According to the passage, who is Harry’s helping hand?

A.Pete

B.His teacher.

C.His brother

D.His parent小题2:Why is Harry kept in a wheelchair all day?

A.Because his legs are broken.

B.Because his leg muscles are weak.

C.Because he is too lazy.

D.Because he likes it.小题3:According to the passage, which of the following about Pete is not true?

A.Pete can clean Harry’s room.

B.Pete can switch lights on.

C.Pete can pull Harry’s wheelchair.

D.Pete can push the button on the school lift.小题4: What does the writer mean by saying “Pete is here when I need a friend.”?

A.Pete is only a helpful tool for him.

B.Pete is with him all the time.

C.Pete is a funny dog to make him happy.

D.Pete is not only a helping hand but also his good friend.

选择题