91. Have you saw someone ___________ (ski) before?
92. Can a shark stop ___________ (swim)? —No, It can't
93. You'd better try ___________ (do) it by yourself.
94. The students kept ___________（talk）about the football match.
95. I had a computer lessons first. Then I went on ___________ (have) tennis lessons.
96. He hopes ___________ (see) the famous football player as soon as possible.
97. The boy kept ___________ (ask) strange questions to his teacher, it made the teacher unhappy.
98. Edison enjoyed ___________ (try) his new ideas.
99. He asked me ___________ (speak) loudly.
100. Students must study hard ___________ (make) our country strong.
參考答案:1.skiing
2.swimming
3.to do
4.talking
5.to have
6.to see
7.asking
8.trying
9.to speak
10.making