When you return __________your studies为啥用at ,而不用to

We wanted to tell them_______these books.A.when return B,when to return C when return D when you return 选择哪一个?为什么 you shall get the book you want this Sunday,____,.according to the record,Mr.brown will come to return it.after?while?when?before I don't know when she___（return）,but when she___（return）I___（let） you know.第二个return可以用“will return”吗?为什么? When did you return to school?的同义句 When ____(be)you born? could you tell me when Mr.Smith returens/will return最后应该用 return 还是 will return? When didi you ___ China?答案上是选return.但return后不应该加to么? when are you ___to your hometown?A.return B.return back C. returningD.returning back Did you return Fred’s call? —I didn’t need to ____ I’ll see him tomorrow.Did you return Fred’s call? —I didn’t need to ____ I’ll see him tomorrow. A. though B. unless C. when D. because I don't know when Jim _____.I'll meet him at the airport when he ____.A.will return；return B.returns；will return C.returned；returned D.will return；returns 说明原因喔 please ---the book ---the library when you finish itA.return,toB.return ,backC.returns,toD.returns ,back you will feel ____ when you see you have made others happy.A.happy B happier C happiness 选哪个?kindness is when we help others without ecpecting anything in return.wh en you show kindness to somebody,you bring out the best in yourself,and you wil you will feel ____ when you see you have made others happy.A.happy B happier C happiness 选哪个?kindness is when we help others without ecpecting anything in return.wh en you show kindness to somebody,you bring out the best in yourself,and you wil We want to know when he ____ from Taiwan.If he ____,please tell us.(return) 时态填空 You dad better return that piano to me tomorrow(同义句转换) ____ ____to return ___ ___ ___tomorrow. You'd better return the book to me next Monday .(同） ____　____ to return ____ ___ ___ next monday when do you have ____ class? You must return the bike to her同义you must ____ the bike _____ to her