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.