Knives are used for cutting things.为什么不能用Knife?

Knives are used for cutting things.为什么不能用Knife? Knives are used for cutting things. knife are using for cutting things 为什么用knife we use knives for cutting things. knives are used ______ things . 英语句型转换1.He used a knife for cutting things.(改为同义句)He ______ These knives can be used for cutting.翻译 3道英语语法题1.____are____for cutting things.A.Kinfe;used B.Knives the kind of_____(机器)are used for cutting things into pieces this kind knife is cutting metal a.used for b.used to c.used ____ are ____ for cutting things. 主动句People use knives for cutting things变成被动句怎么变?