问题
选择题
下图表示人体的一些生命活动，下列有关说法正确的是
A．①过程的细胞核膜核仁始终存在
B．②过程细胞中的遗传物质发生改变
C．③过程中细胞内多种酶的活性下降
D．④过程中原癌基因从激活状态转为抑制状态
答案
答案：C
搜题请搜索小程序“爱下问搜题”
下图表示人体的一些生命活动，下列有关说法正确的是
A．①过程的细胞核膜核仁始终存在
B．②过程细胞中的遗传物质发生改变
C．③过程中细胞内多种酶的活性下降
D．④过程中原癌基因从激活状态转为抑制状态
答案：C
| 完型填空。 | ||||
| There are about fifteen hundred languages in the world. But 1 a few of them are very 2 . English is one of these. Many, many people use it, not only in England and the USA, but in other parts of the world. About 200, 000, 000 people speak it as their own language, It is difficult to say how many people are learning it as a 3 language. Many millions of people are 4 to do so. Is it easy or difficult to learn English? Different people may have different 5 . Have you ever 6 ads of this kind in the newspapers or magazines? "Learn English in six weeks, or give you 7 back...," "easy and funny…Our records and tapes 8 you master English in a month. 7, Of course, it never 9 quite like this. The  only language that seems easy to learn is the mother tongue. We should 10 that we all learned our own language well when we were 11 . If we could learn English in the same way, it would not seem so difficult. 12 what a small child does. He listens to what people say. He tries what he hears. So it is 13 to say that learning English is easy. We must do a lot of practice. And practice needs great effort and 14 much time. Good teachers, records,  tapes, books, and dictionaries will helpful, 15 they cannot do the students' work for him. | ||||
|
