a sharp knife-------一把锋利的小刀所以要问“什么东西”，用疑问词What。满意请及时采纳，谢谢
泰安点金教育为您解答This is a sharp knife. 对a sharp knife提问What is this?
What
Are you sure use a sharp knife to cut the apple？
what is on the table？
这是划线部分么
