My friend has returned from the UK. She ______ at Oxford for four years, during which we communicated with each other on the Internet.
It was she that ________a sharp whistle, which makes ________possible for us to catch the thief.
Which city in England do you think may be called __________Shanghai of ________West?
I’d like Jane, _____Joan, to go to the farewell party on behalf of (代表) our class.
If we________ , we can realize the progress we have made in space research.
They arrived at the farmhouse, in front of which _________.