The traditional approach __________ with complex problems is to break them down into smaller,more easily managed problems.
A modern city has been set up in _________ was a wasteland ten years ago.
Tom admitted ______ in the examination and he was not admitted _____ the school at last.
There have been so many school bus accidents recently.________,people are concerned about the school bus safety much.
________children get older,they become more and more interested in the things around them.
Someone called me up in the middle of the night, but he hung up __ I could answer the phone.