before you enter the teacher's office,you should k____ on the door

you must ____(knock)on the door before you enter 改错.Knock before you enter into the room. always knock on the door before you enter before you e---- the house 用enter 还是entered you should knock at the door before you the room.为什么用enter而不用enter into before you enter the teacher's office,you should k____ on the door Before you enter the teachers office ,you must (k ) on the door first. Before you enter the teaher's office,you should k____ on the door first. you enter the house 重组句子： put / into the locker / your /first / you /enter / bag / the library /before / you had better take off your shoes before ______(enter)the room.填什么 并说明 Don't enter into the room before they tell you to do that.修改病句 must ask(a,an,无)permission before you enter the room选哪个 Your name has to __(sign) before you enter the meeting-room. You should knock at the door before you you _____ the room.【是go into 和 enter都行吗?还是?】 重组句子：put / into the locker / your / First / you / enter / bag / the library / before /.First排第一 Koock at the door before enter the room 中enter要不要变形? please knock at the door before you enter the room（同义句转换）please knock at the door _________ __________the rooom