1,马以草为食
Horses( eat )grass
2这本英语书太难了,我看不懂
The English book is ( difficult ）
3The car zccident ( happened )发生in a town last night
4The boy must be Plilip(改为否定句）
The boy (can't )(be )Plilip
5Let's play chess?改为反义疑问句
Let's play chess ( shall )( we )?
6This is Sun Meng's baseball cap.对画线部分提问
（ Whose）(baseball ) (cap )is this?
希望能够帮到楼主