六、词汇。（本题共8小题，每小题1分，共8分）   

A. 根据句意及汉语提示，写出各单词的正确形式，每空填一词。

63. 49. He is fast _______(sleep), but I can’t go to sleep. 

64. It’s ________ (nature) that teenagers may sometimes quarrel with their parents.

65. The tourists _________ (trap) on the top of the mountain were saved an hour ago.

66. If the man is still ________(live ), we need to ask for a doctor at once.

B. 根据句子意思，用括号中所给词的正确形式填空，每空填一词。

67. Because of the terrible ___________ (灾害)，the boy lost his life.

68. It was very foggy yesterday, there were a number of __________ (事故) in the street.

69. When you are in danger, it is important to make you not be ____ (紧张) and calm down.

70. It is said that the bad milk powder(劣质奶粉)       （引起）the death of over 30 babies.