按要求写出下列单词的相应形式。
(1) do (单三)
(2) have (单三)
(3) class (复数)
(4) sheep (复数)
(5) do not (否定缩写)
(6) doesn’t(完全形式)
(7) work (名词)
(8) drive (名词)
(9) cow (复数)
(10)watch (单三)