问题 问答题 简答题

何谓急性毒性?急性毒性试验的目的是什么?怎样进行急性毒性试验设计?

答案

参考答案:

(1)急性毒性(acutetoxicity)是指机体(人或试验动物)一次接触或在24h内多次接触外来化学物之后所引起的快速剧烈的中毒效应,包括一般行为、外观改变及形态改变,甚至死亡效应。

(2)急性毒性试验目的:可确定受试物的致死剂量、有效剂量和某种效应的急性阈剂量等表示剂量―效应关系的参数。

外来化学物的急性毒性试验是认识与研究其对机体毒性效应的第一步。

(3)设计:急性毒性试验设计包括选择动物种类、受试物剂量、观察指标及计算方法等。

选择题
阅读理解

I woke up late and had breakfast in a hurry. I had never been late and didn’t want my boss to be unsatisfied.

However, it seemed that day wasn’t a lucky one for me from the very second I left my flat. The moment I wanted to rush downstairs one of my stiletto heels(细高跟) broke. I had to return to change my red shoes. I also had to change my purse and other little things that I had tried to match the red shoes. I was sure I would be late for work.

On my way to work I had to wait for over half an hour because of an accident. I had no choice but to wait. I phoned my boss and he told me that it was no problem, but he needed me for the meeting with the Japanese clients(客户) that morning.

Finally, I arrived at the office one hour later. I had to keep calm and be fresh for the meeting to make the clients sure that our plan was the best for their future commercial(商业的) project. However, when I was going to present(介绍) it to the clients, I found that I left the plan I had made the night before at home. I was about to get angry when I realized that I had a draft(草稿) of it in my office.

At last, the presentation came to an end and it proved to be a success. But I had to say that I had a terrible day, full of incidents.

小题1:Which of the following is NOT the reason for the writer’s being late for her work?

  1. She got up late in the morning.
  2. She changed her purse and other little things.
  3. One of her shoe heels broke.
  4. She had to wait for her friend for half an hour..
小题2:According to the passage, what could we learn about the writer?

  1. Her boss was very angry with her.
  2. She often arrived at her office on time.
  3. She left her plan on the bus.
  4. She was nervous at the meeting.
小题3:What did the clients think of the writer’s presentation?

A.Dull.

B.Just so-so.

C.Excellent.

D.Terrible.