48.最后: at last

47.自然保护区: nature reserve

46.和平地生存：live in pease.

45. 查找它: find it out

43.使得某人发狂: make sb mad

44: 把它变脏: make it dirty

42.听到那个消息很难过：

I/m sorry to hear that.

41.究竟 : on earth

40.在野外:　　 in the wild

39.为某人而工作: work for sb

38.污染河流: pollute the rivers