题目

若 ＝3，求 的值. 答案：解：∵ ba=3 ， ∴b＝3a， ∴ a+ba−b ＝ a+3aa−3a=4a−2a=−2 .1．Are there any ______________ （相似处） between the two? 2．Athens is known as the birthplace of western __________________ （文明）. 3．There was a _______________ （可能性） that a huge tidal wave would flood half the island. 4．There seems to be a highly _______________ （感染性的） type of flu going round. 5．No one knows what the city of the future will look like and making ______________ （预测） is a risky business. 6．  _____________ （出口） to many countries, the cotton goods produced by this factory has a wide variety of consumers. 7．As the cars come into the centre, video cameras record their _______________ （登记） numbers, and these are checked with a list of drivers who have paid the charge for that day. 8．______________ （包括; 卷入） in the case unexpectedly, the man felt upset and hopeless. 9．The Chinese discovered that the gas ______________ （逃脱; 漏气） from the tube could lift it into the air. The idea of the rocket was born. 10．The architect is ________________ （乐观的） about the effect of the house on the environment.