______ it have been the failure to pick up directions from the ground control that caused the air crash?
Do you want a friend ______ you could tell everything to?
—May I see your ticket, please? I think you ________ in my seat. —Oh, sorry. My seat is upstairs.
The teacher told the kids that light ________ faster than sound.
Have you heard the traffic ________ that happened in Yatai Street last week?
—Excuse me, can you tell me the way to the supermarket? —OK. Go ____ along the street, turn left and you'll see a tall building. That is the supermarket.