问题
单项选择题 A1/A2型题
牙骨质由牙胚的哪部分形成（）
A.成釉器
B.牙蕾
C.牙囊
D.牙板剩余
E.牙 * *
答案
参考答案：C
搜题请搜索小程序“爱下问搜题”
牙骨质由牙胚的哪部分形成（）
A.成釉器
B.牙蕾
C.牙囊
D.牙板剩余
E.牙 * *
参考答案：C
| 完形填空。 | |||
| 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 U. S. A, but in other parts of the world. About 200, 000, 000 speak it as their own language. It is difficult to say how many  people are learning it as a 3 language. Many millions are 4 to do so. Is it easy or difficult to learn English? Different people may have different 5 . Have you ever 6 the ads of this kind in the newspapers or magazines? 'Learn English in six month, or your 7 back ...' 'Easy and funny? Our records and tapes 8 you master your English in a month. 9 the first day your 10 will be excellent. Just send ..." Of course, it never 11 quite like this. The only language that seems easy to learn is the mother tongue. We should 12 that we all learned our own language well when we were 13 . If we could learn English in the same way, it would not seem so difficult. 14 what a small child does. He listens to what people say. He tries what he hears. When he is using the language, talking in it, and 15 i  n it all the time, just imagine how much 16 that gets! So it is 17 to say that learning English is easy, because a good command of English 18 upon a lot of practice. And practice needs great effort and 19 much time. Good teachers, records, tapes, books, and dictionaries will 20 . But they cannot do the student's work for him. | |||
| ( )1. A. not ( )2. A. difficult ( )3. A. native ( )4. A. learning ( )5. A. questions ( )6. A. found ( )7. A. knowledge ( )8. A. make ( )9. A. From ( )10. A. spelling ( )11. A. happened ( )12. A. know ( )13. A. students ( )14. A. Imagine ( )15. A. using ( )16. A. time ( )17. A. hard ( )18. A. depends ( )19. A. uses ( )20. A. do | B. quite B. important B. foreign B. enjoying B. problems B. watched B. time B. help B. On B. grammar B. know B. remember B. children B. Mind B. thinking B. money B. easy B. tries B. takes B. work | C. only C. necessary C. useful C. trying C. ideas C. noticed C. money C. let C. Since C. English C. seemed C. understand C. babies C. Do C. trying C. language C. funny C. has C. gets C. help | D. very D. easy D. mother D. liking D. answers D. known D. English D. allow D. After D. pronunciation D. felt D. think D. grown-ups D. Think of D. practicing D. practice D. silly D. takes D. costs D. master |