49. He has no concept of wrong and right.= He can't tell right from wrong.　 他没是非观念。

48. concentrate on= focus one's attention/mind on　　　 concentrate oneself on　

47. conceal the truth 隐瞒真相　　 conceal sth from sb　 向…隐瞒…

46. compose a song/ music/poetry　　　　　 be composed of = be made up of = consist of

45. complain to sb of / about sth 抱怨　 complain to sb that　 make complaints to sb about...

44. a sense of competition　 一种竞赛意识

43. compare A with B　 拿…与…比较　　 　compare A to B　 把…比做…

42. a common name　　　 a common disease　　　 the common sense 常识　　

have sth in common　 有…共同之处　　 get a general idea of　 对…有大致了解

communicate with sb　 通讯　　　 communicate sth to sb 把…传递给…；向…表达…

41. commit murder　 犯凶杀　 commit an unforgivable error　 犯不可原谅的错误

40. a commercial course 商科a commercial theater以赢利为目的的 a commercial radio