Visual FoxPro中的DO CASE-ENDCASE语句属于( )。A) 顺

用所给动词的适当形式填空

1. Mozart __________(make) a lot of famous music.

2. His father __________(die) for five years.

3. There are many __________(music) playing the piano.

4. He __________(teach) us English well, doesn't he?

5. Please ask him __________(not watch) TV before he finishes his homework.

6. It's best __________(read) English in the morning.

7. If it __________(rain), my father __________(take) me to school in his car.

—Could we see each other at 9 o'clock tomorrow morning?

—Sorry, let's make it ______ time.[ ]

A. other's    

B. the other        

C. another    

D. other

如图所示，用一根长为l的细绳一端固定在O点，另一端悬挂质量为m的小球A，为使细绳与竖直方向夹30°角且绷紧，小球A处于静止，对小球施加的最小的力是(      )

A．mg

B．mg

C．mg

D．mg

结核病化疗方案中E字母对应的药品是（）

A.链霉素

B.乙胺丁醇

C.异烟肼

D.利福平

E.吡嗪酰胺

实验设计的原则有哪些？