题目内容：

根据所给首字母或汉语提示完成单词。

1.The old s                 is, "Who laughs last, who laughs best!"

2.I had a toothache, so I must go to see the                （牙医）.

3.It's hard to                （选择） the best answer to the question.

4.He saw some                （老鼠）in the street yesterday.

5.My brother Jack is more                （外向的）than me.