名词单数变复数练习题1. 请把下面的名词单数变复数。cat_ dog_ desk_ key_ boy_ story_ family_ bus_ box_ watch_ potato_ tomato_ bed_ brush_ wife_ knife _teacher_ sister_ plane_ school_2. 把下面的单数句子变成复数句子。1) This is a book. These _2) It is a red apple. They_3) That is a eraser. Those。3. 填入所给名词的正确形式。1)I have too_(knife)2)There are many_(box)3)She has three_(ruler)