51.　 How sweet her voice _____(听起来)!　

50.　 Pop music is the ______(种类) she likes most.

49.　 When water freezes and becomes ________(固体), we call it ice.

48.　 Some _________(士兵) got wounded in the war.

47.　 He is a danger to the ___________(社会).

46. Things are not going very __________(顺利).

45. While studying, I _________(闻) something burning.

44.　 She had a __________(轻微) headache.

43.　 He was so tired that he ______(睡) like a log, that is to say, he had a sound ____(觉).

42.He is already in his ___________(60).