—Is it possible(可能的)that we will be late for the first class?        

—                 .[ ]

A. I hope it        

B. I think it      

C. I’m afraid so      

D. I hope so

对于实数λ≠0，非空向量及零向量，下列各式正确的是（）．

A.选项A

B.选项B

C.选项C

D.选项D