第13题: [单项选择]Linda did not have time to go to the concert last night because she was busy ______ for her experiment. A. to prepare B. to be prepared C. being prepared D. preparing 参考答案:D 答案解析:be busy doing something是正确的表达方式,故选项A和B是错的。从本题的意思来看并没有被动的含义,因此选项C也是错的。
A. new electronic instruments for planes B. new radio sets for RAF bombers C. an electronic detecting device D. a radio directing and ranging device 参考答案:D 答案解析:[参考译文]实际运用这一原理结果出现了无线电探测器。 [试题分析]本题考查对细节的理解。 [详细解答]从文章的最后一段我们知道,因为使用电波告诉皇家空军飞行方向和飞机距离,所以这种装置就被