Why you be so stubborn? You should think over my advice on this matter.
A. may
B. shall
C. dare
D. must
网友回答
A. may
B. shall
C. dare
(答案→)D. must
解析：考查情态动词。must硬要，一定要。如：If you must go, at least wait till the rain stops. 如果你坚持要走，至少也要等雨停了再走。句意：你为什么一定要那么固执？你应该听听我在这件事上的建议。故选D。