He can't find his key.He ---------- them.A.must lost B.must

He can't find his key.He ---------- them.A.must lost B.must Our teacher must be in his office,A mustn't he B can't he C He must be from Africa,( )can be seen from his hat. A.it B.t he lost his key t----- the door. He must be fifty,________?A.mustn't he B.can't C.must he D.m He must have finished his homework,he A,mustn't B didn't Cha He must have lost hiswatch at the moment,__he?A.didn"t B.mus he must have finished his project last week,——?A.hasn't he B He doesn't have a bike.He ---walk back home.a.can b.must c.h He doesn't know how he_____improve his English. A.must B.has Bob must be at home,________?A.mustn't he B.can't he C.isn't He must have lost his watch yesterday,_______he?