Don't come in before knocking at the door.before 后面的 knocking用的对吗?

Don't come in Don't come in before knocking at the door.before 后面的 knocking用的对吗? Don‘t stand_____the room.Come in,please. Don't stand o____.Come in please Don‘t stand_____the room.Come in,please. Don't stand o____ .Come in don,t stay ( ) please come in don't stay o___.come in,piease Don't stand ____the room.please come in.A.in front of B.in the front of C.before D.at the front of “18 years old before don't fall in love! Don't worry.I will come back before long.改同意句Don't worry.I will_____ _____.怎么填空 promise don't come love don't come Don't come promises don't come Don't come any Don't worry.The train is_____(come) in three minutes. Don't worry about me.It won't be long_______I come back.A.since B.after C.before D.when