50．What have you done today to make you feel ________(自豪)? It's never too late to try．

49．It may be a great experience to study a________，and you'll find people in another country，are very friendly and helpful．

48．It's true that when you are out of job，it's ________(无用的)to complain．

47．It is normal for you to feel ________(紧张)when you have to tell your own story to many people．

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．

根据提示写出所缺单词，使句意完整正确。

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