根据下列句子中的首字母，写出正确的英语单词。限填一词。

71. Father’s Day is on the t           Sunday in June.

72. The traffic during the rush hour is much b           than usual.

73. We must learn to look after o          when we are alone at home.

74. S               in the river in summer is good for our health.

75. What a nice girl Sally is! She often h          to do the housework.