They are busy ( ) a research ( ) environment A to,on B on,at C with,on D with,at 选哪个 为什么

They ()very busy.a:both.b:all are.c:are both.d:are all. they are busy ----------model planes 填词 They are v-- busy(忙） They are busy p______ using computers now Most people are so busy making a living that they forget to make a life. they are ___ busy today A:readey B:do C:really What are they busy 后用加doing吗?（Wat are they busy doing?) 是They are all busy and happy 还是They are all happy and busy? They are busy every day,so LinTao often help __with the housework.A.they B.them C.their D.theirs our teachers are very busy they have not had a day___ for a weekour teachers are very busy they have not had a day ____ for a weekA,away B,on C,off D,of They are busy ________ (have) lunch.They are busy to have lunch.为什么看见有写的They are busy having lunch.都是对的么?为什么? are busy preparing可以换成（）A、are busy to prepareB、are busy withC、are busy to preparingD、are busy for prepare they are busy -------------model planes.A make ;out of B:cut;out of C:make ; out D:any;some Some of ____(they) are busy with the orange picking. They are always busy with lessons.同义句 theachers often c_ they are too busy every day They are busy ____(skate ) all the morning. They are busy all day这句话什么意思