Our teachers （）us already that washing hands often will help us prevent the A-H1N1 Flu .
问题描述：
Our teachers （）us already that washing hands often will help us prevent the A-H1N1 Flu .
A.tell B.told C.have told D is telling
答
C
有already,所以用完成时 .
A.tell表示一般现在时
B.told 表示过去时
C.have told表示现在完成时,过去完成时用had told
D.is telling表示现在进行时
所以选C