根据下列句子及所给单词的首字母，写出各单词的完全形式（每空限填一词）。

71.　 A c_________ means 100 years.

72.　 There are fifteen minutes in a q________.

73.　 Smoking is not a_________ in our school.　

74.　 Lin Shuhao is the p ______ of China.

75.　 You can’t w_______ every time. Try again and you’ll make it.

76.　 The doctor saved many people’s l_________.

77.　 He was late and m_______ the early bus.

78.　 I think r_______ will help us do the housework in the future.

79.　 The p_______ in this city is very serious. People even don’t have clean water to drink.

80. In g______, we have made great progress in English.