“三好”的内容是管好、（）、维护好。

王晓要代表学校参加省里组织的一次演讲比赛，她非 常紧张，但她反复告诉自己：“我有这个实力，不要紧张，我一定能行！”最后赢得了比赛。

判断：______________________________________________________________________________________

理由：__________________________________________________________________________________________________________________________________________________________________________________

—I'm afraid I can't return he the book to you before Tuesday.

—________.[ ]

A. Don't be afraid

B. You are welcome

C. Take your time

D. Be careful

圆规两脚间的距离为2厘米，所画圆的面积为______平方厘米．如果将这个圆平均分成若干份，剪拼成一个近似的长方形，这个近似长方形的长是______厘米．

The long-run production decision differs from the short-run production decision in that:（）

A. variable costs can be changed in the short run but not the long run.

B. variable costs can be changed in the long run but not the short run.

C. fixed costs can be changed" in the long run but not the short run.

汽车前轮摆振可能有以下哪些原因引起的（）。

A.轮胎胎压低

B.四轮定位失准

C.车轮轴承过紧

D.方向盘变形