he was the first boy in our class__having__(have)a computer.
let's go and see who__is singing__(sing)in the next room.
他解释了他开会来迟的原因.
He___explained why__________he was late for the meeting.
我喝了那啤酒后昏昏欲睡.
That beer___made me sleepy__________.
have difficulty with sth对吗?
不对 应该是have difficulty in sth.
希望能够帮到楼主