关键语法
—What’s the matter________(of；with)him？
—He has a fever．
I think you should________(lie；lying)down and rest．
When I walked past her classroom，I saw her________(study；studying)in the classroom．
She expects him________(come；to come)to see her tomorrow．
To his________(surprise；surprised)，that boy has passed the exam．
All the students agreed________(going；to go)to the mountains on Saturday．
Thanks________(at；to)your help，I could work out that math problem．
They had trouble________(finding；to find)who broke the window．