The floor is wet. Who’s going to ?A. mop up itB. mop up themC. mop it upD. mop them up

问题补充：

The floor is wet. Who’s going to ?

A. mop up it

B. mop up them

C. mop it up

D. mop them up

答案：

A. mop up it

B. mop up them

(答案→)C. mop it up

D. mop them up

解析：本题前句主语是单数，故后句用it来代替，mop和up搭配，代词必须位于两者之间，故本题选C。