46．When we find lots of university graduates ________（大学毕业生）cannot find the job they like，we begin to know the problem is ________（严重的）

45．It's our duty to prevent the water ________（污染）and make sure that everyone has clean water to drink．

44．Mr. Cheng，our headmaster usually walks to school every day because his home is quite c________ to the school．

43．They make sure to keep all the food s________ after the milk scandal（丑闻）．

42．If you feel a bit t________ after a day's hard work，I think you should have a holiday to relax yourself．

41．She spends much time practising dancing just because of her dream-to be d________．