He must ________ a shower, for I can hear the water ________．

He must ________ a shower, for I can hear the water ________．

A.have; run

B.be having; run

C.have; running

D.be having; running

答案及解析： D

must be doing是用情态动词猜测正在发生的事，hear the water running意为“听到水(正)在流”。