Every 40 minutes we will take a 20-minute break, ______ your guide will give a short talk on different aspect of the Great Wall.
_______ in the Moluyuan on a March afternoon, he could feel the warmth of spring.
You should correct all the mistakes as soon as possible before the book _____.
How can they learn anything _____ they spend all their spare time watching television?
We congratulated Jerry ____ the championship.
It took my father half an hour to finish ____ my bike.