切换“清除屏幕”操作对应的默认快捷键是（）。A.CTRL+9 B.CTRL+2 C.

根据汉语提示，用适当的单词填空。

1. Her father works in the ________ (医院). He is a doctor.

2. ________ (美国人) eat Turkey with their families on Thanksgiving.

3. Yesterday they ________ (参观) the Summer Palace.

4. My grandfather likes ________ (京剧) very much but I don't like it.

5. Look at the sun! You had better wear your ________ (太阳镜).

骑跨伤易伤及（）。

A.球部 * *

B.膜部 * *

C.垂部 * *

D.前列腺部 * *

E.膀胱颈部

After so many hardships, the scientist             his motherland at last.

A．set on his foot

B．set foot on

C．set feet on

D．set his feet on

未取得增值税专用发票，（）抵扣进项税额；也不得差额计税。

A.可以

B.不可以

C.一定情况下可以

D.以上选项都不对

盘式结构的刀库，刀具可以沿刀库的轴向、径向或斜向安放，其中沿轴向安放的刀库结构最为紧凑。