He has to find his keys. 改为否定句
问题描述：
He has to find his keys. 改为否定句
My uncle can pull some tabes at the same time.改为否定句
Ben has to go home now.改为一般疑问句
答
1 He doesn't has to find his keys.
2 My uncle can't pull some tabes at the same time.
3 Does Ben have to go home now?