问题

Sam is doing some ______ about the ancient Silk Road.

A:exercise
B:operations
C:research
D:experiments;

正确答案是：

同类题型

We need to ______ after eating to have good teeth.

I didn’t tell my parents the secret yesterday. — But you ______.

Press the button when the light goes on- you will soon__ it. [ ]

There will be a computer ______ a computer ______ the future.

Will you stay for the dinner?—Sorry,__________. The cookers I bought online will be sent to my house this afternoon.