人口的数量常常随环境资源的改变而发生波动。右图为人口自动调控图（注：环境中的人口容纳

错畸形发生的早期通常采取何种矫治方法（）。

A.预防性矫治

B.阻断性矫治

C.一般矫治

D.外科矫治

E.以上都不是

补全对话。

A: Good morning. Sit down, please.

B: Morning, doctor.

A: What's the matter 1______ you?

B: I was caught in the rain yesterday. I've got a bad cough and my head hurts.

A: Do you have a fever?

B: Yes, My 2______ is 380℃. O fee; terrible.

A: Oh, let me see... There's nothing serious. You just have a cold. Have a good rest,

    and you'll be fine soon.

B: Thanks, I will. Any other suggestions?

A: You 3______ better choose your clothes according to the weather report.

    The weather often changes in summer.

B: 4______ will the weather be tomorrow?

A: Now, we're in the season of rain. 5______ still be rainy tomorrow.

    When you go out, please take an umbrella.

甲、乙、丙、丁四人进行射箭测试，每人10次射箭成绩的平均数都是8.9 环，方差分别是s_甲²=0.65，s_乙²=0.55，s_丙²=0.50，s_丁²=0.45则射箭成绩最稳定的是    

何为塑化？塑化与熔化有何区别？

FIDIC施工合同条件规定，承包商完成工程并准备好竣工报告所需报送的资料后，应提前21天将某一确定的日期通知工程师，准备竣工验收，工程师应指示在该日期后( )天内的某日进行验收。

A．7

B．14

C．28

D．42