Go and ________ when the train is leaving．

Go and ________ when the train is leaving．

A.be sure

B.make sure

C.be sure of

D.be sure that

答案及解析： B

解析：

该题考查make sure的用法，be sure of表示相信某事，be sure that表示敢肯定某事，而make sure是确信，确保，弄准确。