问题

I can’t get through to the general manager’s office anyhow. —- The line is busy. Someone ___________ the telephone.

A:can have used
B:can use
C:must have used
D:must be using

正确答案是：

同类题型

The new computers_______to the village school as present last month

According to our teacher, we should take detailed notes in class because they are more __________ than our memory.

Did you scold him for his mistake?— Yes, but _____ it.

I want to have ______ English pen pal.

Mum is ill in bed now. I must ____________her.