下列对滥用抗生素造成病菌产生抗药性的解释，不符合达尔文的自然_爱下问搜题

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问题选择题

下列对滥用抗生素造成病菌产生抗药性的解释，不符合达尔文的自然选择学说的是[ ]

A．细菌在繁殖过程中一般会由于基因突变产生各种可遗传的变异

B．抗药性强的变异病菌在使用抗生素时明显表现为有利变异，能有更多繁殖后代的机会

C．抗药性强的变异病菌通过繁殖产生的后代中也会有抗药性较差的个体

D．抗生素不断淘汰抗药性弱的个体，保留抗药性强的个体，使抗生素效果下降

答案

答案：A

完形填空

完形填空。

     I am a student in Grade Three. I began to learn English the year before last. English isn't very   l   to learn. But I like it very much.
     2   do I study English?
     In the first year; I found   3   very difficult to memorize new words. At first I   4   a lot of time on them. I learned new words only   5   reading and writing them,   6  a few days later I forgot them. Later, I came to know how to do it well. I paid more
attention to   7   and spelling.
For example :

8 I have learned a lot of new words by heart. Every morning after I get up, I do some reading. At school I 9 to speak English with my classmates and go over 10 I have learned. Nothing is too hard if you put your heart into it.

( )1. A. hard
( )2. A. Why
( )3. A. this
( )4. A. took
( )5. A. with
( )6. A. and
( )7. A. pronunciation
( )8. A. By the way
( )9. A. join
( )10.A. that

B. excited
B. What
B. it
B. paid
B. for
B. but
B. words
B. In this way
B. lose
B. what

C. easy
C. Unless
C. that
C. spent
C. as
C. then
C. reading
C.. To begin with
C． try
C. which

D. fast
D. How
D. /
D. cost
D. by
D. however
D. writing
D. Later on
D. realize
D. when

选择题

--- John, where are the cookies? Don’t tell me you ate them all!

--- ______ I couldn’t help it. They were so good.

A．Yes, I did.

B．No, I didn’t.

C．Yes, I have.

D．Why? Sounds strange!