You must your papers before you hand them in.A. go downB. go acrossC. go outD. go through

问题补充：

You must your papers before you hand them in.

A. go down

B. go across

C. go out

D. go through

答案：

A. go down

B. go across

C. go out

(答案→)D. go through

解析：本题考查动词短语。句意：你必须仔细检查试卷后才能上交。 go through在此句中的意义为“检查”。