be careful when crossing the street!A. MustB. ShouldC. Ought toD. Do

发布时间：2020-08-17 13:16:02

     be careful when crossing the street!
A. Must
B. Should
C. Ought to
D. Do

网友回答

A. Must
B. Should
C. Ought to
D. Do
解析：加强祈使句的语气,不管动词是系动词还是行为动词,都在动词前加do。  
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