.It took them half an hour to go the crowd.A. throughB. acrossC. crossD. out

问题补充：

.It took them half an hour to go the crowd.

A. through

B. across

C. cross

D. out

答案：

(答案→)A. through

B. across

C. cross

D. out

解析：through表示从中间通过；acoss表示通过时，是在接触面的通过；cross是动词“穿过”，本题不需要动词；out“外面”，与题意不符。又因为，the crowd是“群众”，应该从中间通过，故用through，所以本题选A。