从下面方框中选择一个适当的词填空，并将其正确形式写在答题卡对应位置，每空一个词．每词只用一次．

71．Eric spends half an hour 　 　TV every evening．

72．My brother didn't realize the 　 　of English until he began to work in a Canadian factory．

73．She 　 　where she parked her car yesterday，so it took her a long time to find it．

74．Every day after supper，my father 　 　his dog in the park．

75．Smoking is 　 　to your health，so you'd better give it up．

76．The house is 　 　the same as it was 20years ago．

77．This T﹣shirt is kind of small．Can you show me a 　 　one？

78．Our teacher gave us some 　 　advice on how to learn English well

79．The strueture（结构）of DNA was one of the most important 　 　in the twentieth century．

80．He said he would drive rne home，but I turned down his 　 　．