it must be morning,____ the birds are singinga.becauseb.asc.sinced.for请简述四者区别

10.It _______(be) snowy this morning.You must wear more clothes. It must be morning now,for birds are singing.句中的for能不能换成because?为什么? It Must Be?歌词 it must be Once it is worked out,the plan must be carried out同义句转换：Once _ _,the plan must be carried out Since the road is wet this morning,---------last night.A it must rain B it must have rainde C it must be raining D it must have been raining 选什么 为什么 Since the road is wet this morning,---------last night.A it must rain B it must have rainde C it must be raining D it must have been raining 11. Sincestthe road is wet this morning,last night()选择谢谢A it must be raining B it must rain C it must have rained D it must have been rained You must be _(careful) than before. it must be morning,____ the birds are singinga.becauseb.asc.sinced.for请简述四者区别 It _ Mary who was in the room.I'm sure it _— It ___ Mary who was in the room.— I'm sure it ___.A.can't be,can't be B.must be,mustn't beC.must be,can't be D.can't be must be What bad weather it is!We hope it _(mnot last) long.Your mother _(not look) well.She must be _(bad) ill.If she _(feel) worse by lunch,you'd better _(send) her to hospital. It Must Be Love 歌词 It must be some catch. It must be him 歌词 it must be _____(interest) it must be rainy( )( )(随后) it must be imagination 歌词