When you are home,give a call to let me know you safely.

问题描述:

When you are home,give a call to let me know you safely.
A.are arriving B.havearrivedC.had arrivedD.will arrive
请问此题为什么用完成时啊?答案是B
谢谢

考查动词时态.根据题意可知,这里要表达“回家后打电话确认已经安全到达”,所以应该用现在完成时,答案为B项.A项和D项均表示将来,但没有“完成”之意,所以排除;C项为过去完成时,不符合题意,所以排除.
[答案]B