1 . 他一定以为我在开玩笑。
He _________ I was joking.

2 . 我的姐姐回家时满脸笑容。她一定通过驾照考试了。(情态动词 + have done)
My sister came home with a broad smile on her face. She ____________________________.

3 . 你很熟悉这个城市，你一定在这里待了很长时间。(must)
You are very familiar with the city; you ________ here for a long time.

4 . You_______________(一定有过一些时刻) when you were disappointed. （“must have done sth ”意为“一定做过某事”）

5 . Tom didn’t respond to any of my calls. Something ____________________________ to him.  
汤姆没接我的电话。他一定是出什么事了。

6 . 他肯定是受到了惩罚，因为他今天不高兴。
He __________________for he is upset today .

7 . 我们一定是走错路了，因为道路变窄了。(must have done)
________, because the road became narrow.

8 . 既然没有人帮助他, 他一定是独自完成了这项研究。(must have done)
Since nobody gave him any help, he ________.

9 . 我相信他肯定遇到意外事件了，否则他会按时到的。(must have done)
I believe ______; otherwise he would have arrived on time.

10 . 汤姆昨晚一定熬夜到很晚。他是那么困以至于刚才我们在一起唱歌的时候他睡着了。
Tom________ last night. He was________ he fell asleep when we sang a song together just now. (must)