问题 名词解释

水产养殖动物病害防治过程中有哪些给药方法,分别简述它们在使用上的优缺点。

答案

参考答案:

(1)药物悬挂法:又称挂袋(篓)法,将药物装于袋或篓内,挂于饵料台,以预防疾病的方法。

优点:操作简单、用药省、对水影响小。

缺点:只能局部消毒灭菌。

(2)浸洗法:放入药液中浸一段时间、苗种消毒、转池、网箱等常用。

优点:用药省、对水质危害少。

缺点:对水体病原无作用、操作稍繁。

(3)全池泼洒法:将药物兑成一定浓度后全池泼洒。

优点:对病原杀灭彻底。

缺点:用药大、危害水生生物、污染环境。

(4)口服法:将药物拌饵投喂。

优点:操作方便、可杀体内病原。

缺点:重病者无效、水体病原无效。

(5)注射法:包括肌肉注射和腹腔注射。

优点:药效好。

缺点:操作难、易伤鱼、幼苗无法使用。

阅读理解

阅读短文,根据其内容回答问题。

    Many people have jobs. They go to work nearly every day. Some people are lucky. Either they have

very interesting jobs or they make a lot of money Most people are not so lucky. Either their jobs are not

very interesting or they don't make much money. 

    The most interesting jobs are often the most difficult. People take a long time to learn how to do them.

Doctors study for at least six years after finishing school. 

     Some young people have interesting and high-pay jobs. Many young players do their work successfully.

Football and tennis stars are usually under 35 years old. Older people usually can not play these sports very

well. They cannot move fast enough. Golf, however, is a good sport for older people. Many golf players

are quite old, but they can play it successfully.

     Most people work until they are 60 or 65 years old. Then they retire (退休) and have a lot of free time.

Some people never retire though. These people usually have very interesting jobs Writers, artists, scientists

and actors (演员) usually work until they die. Their work is their life.

1.Do most people have interesting and high-pay jobs?

     ______________________________________________________________________________

2.Why do some jobs have to be taken a long time to learn?

     ______________________________________________________________________________

3.What sports are young people good at?

     ______________________________________________________________________________

4.Why is golf a good sport for older people?

     ______________________________________________________________________________

5.When do some people who have interesting jobs retire?

     ______________________________________________________________________________

单项选择题 B型题