1.D [must提问 回答：肯：must 否：needn't〕
2.be good at doing [擅长于...且at是介词,所以用doing〕
3.B [late是形容词 do是助动词,不能直接跟late,加个be作动词；to school(to+地点)作目的状语]
4.是why not do [why not do=why don't you do=how about doing=what about doing]
5.A [is是be动词,后跟adj.,且sunny shine shining只能作表语〕
6.A [只有on后加学科,指在...方面〕
7,8题并答．should/must是情态动词,后只跟do．