题目

86. ______ ______ to ask your questions. 轮流问你们的问题。 87. I believe _______ taking exercise. 我认为锻炼对身体有好处。 88.Nowadays, most of the young don’t _______ _______ Peking Opera.  现如今大多数的年轻人不喜欢京剧。 89. ________ _______ duty, he chose to undertake. 面对责任，他选择承担。 90. The government has ________ ________ to bring down the prices of houses so that people can afford them. 政府已经努力降低房价让人们买得起房子。 91. As far as I can see, ______ ______ no possibility that he will win the t8．如果声源每分钟振动60次，那么它的频率就是60Hz．某同学练声时的发声频率是400Hz，他的声带每秒振动400次．