______aloud so that everyone can hear you clearly.A.singing B.to sing C.sing D.sang 为什么?从哪里看出是祈使句啊?

问题描述:

______aloud so that everyone can hear you clearly.
A.singing B.to sing C.sing D.sang 为什么?
从哪里看出是祈使句啊?

C.祈使句.撇去so that从句不看,如果选A或B的话,主句就没有谓语形式的动词了,也就不成为句子了.而D的时态不对.选C,也就是祈使句.