问题 问答题 简答题

简述植物细胞大规模培养反应器的类型及原理。

答案

参考答案:

机械搅拌式反应器:利用机械搅动使细胞得以悬浮和通气;

鼓泡式反应器:从反应器底部通入无菌空气产生大量气泡,带动培养液循环;

气升式反应器:利用通入反应器的无菌空气带动培养液循环;

光生物反应器:植物体内的多种酶需要光照的刺激和诱导才能合成或表现较高的生理活性;

转鼓式反应器:通常是通过转盘或转鼓的旋转达到混合的目。

阅读理解

“Memorize (记住) these words.” “Learn this spelling rule.” “Don’t forget about the exam tomorrow.” You remember things every day, but how do you do it?

When you want to call a store or an office that you don’t call often, you look in the telephone book for the number. You dial the number, and then you forget it! You use your short-term (短暂的) memory to remember the number. Your short-term memory lasts about half a minute. However, you don’t need to look in the telephone book for your best friend’s number because you already know it. This information is in your long-term memory. Your long-term memory has everything that you remember through the years. The major reason for forgetting something is because you do not learn it well at the beginning. For example, you meet some new people, and right away you forget their names. You hear the names but you do not learn them, so you forget them.

小题1:You remember things every day, but you also forget things easily because you use _______ remember them.

A.your long-term memory

B.your short-term memory

C.the telephone book

D.your notebook小题2:How long does the long-term memory last?

A.About half a minute

B.About 60 minutes

C.As long as you live

D.Through many years小题3:Your long-term memory includes _________.

A.only your best friend’s telephone number

B.all information you read on the newspaper

C.almost everything that you remember through the years

D.the names of the new people you meet for the first time小题4:What does the underlined word “dial” mean in Chinese?

A.拨打

B.背诵

C.抄写

D.默写小题5:According to the passage, people forget things mainly because _________.

A.they are too lazy to remember them

B.they don’t have a long-term memory

C.they only have a short-term memory

D.they don’t learn them well at the beginning

单项选择题