轻度错牙合与功能发育影响不大者，可在此期暂不作治疗。应是哪一_爱下问搜题

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问题单项选择题

轻度错牙合与功能发育影响不大者，可在此期暂不作治疗。应是哪一期（）

A.替牙期

B.恒牙早期

C.恒牙期

D.青春期

E.成人期

答案

参考答案：A

解答题

写出下列命题的逆命题、否命题、逆否命题，并指出他们的真假：若xy=0，则x，y中至少有一个是0．

补全对话，情景问答

给下列的问句选择合适的答语。

( ) 1. May I go shopping?
( ) 2. How far is it from Shijiazhuang to Beijing?
( ) 3. How far is it from Beijing to New York?
( ) 4. Is a bicycle faster or slower than a train?
( ) 5. When do you arrive in shanghai?
( ) 6. What is one thousand and twenty-seven?

A. Yes, you may.
B. On May third.
C. 278 kilometres.
D. I don't know.
E. It's 10: 27.
F. It's slower than a train.