Not until ________ her dark glasses ___________ she was a famous film star.

Only by practicing a lot _____ our English well enough to communicate with foreigners.

So involved with computers ____ that the leaders at the summer computer camps often had to force them to break for sports．

Only when your identity has been checked ________.

Before I left home, my mother taught me ________some simple dishes, such as noodles and garlic with vegetables.