the police(is knocking)(are knocking)at the door填哪个
who is knocking at the door?
1.----Who is knocking at the door
Listen!Who is knocking at the door?
--Listen! Someone is knocking at the door.
单句改错 who is the men knocking at the door
Someone is knocking at the door.____ is it?
There is someone knocking at the door.为什么用“knocking”,要加“ing”
Someone is knocking at the door,but who can____ be?
"Who's knocking at the door?" "______ is Kate."
Who______ it be that is knocking at the door?
Someone is knocking at the door._must be Tom
someone is knocking at the door.who [ ]it be?