_____ economic, political and cultural differences, it is difficult for China and America to fully understand each other.
We all write _______ , even when there is not much to say.
It is believed _______ he has gone to Shanghai. The problem is ________ we can’t get in touch with him.
From the cheers and shouts of _________, I gathered that he was winning the race.
—How did you ________ with that idea? —I read a book.
The Open University can _______ you with different kinds of free instructions.