After series of unsuccessful attempts, he has finally passed driving test.A. the , theB.

After series of unsuccessful attempts, he has finally passed driving test.
A. the , the
B. a, the
C. the , a
D. / , a

A. the , the(答案→)B. a, theC. the , aD. / , a解析：句意:经过一系列失败的尝试,他最后终于通过了驾驶考试。a series of 一系列的，一连串的，因此第一空用不定冠词a,表示“一”。第二空修饰driving test 表示特指，因此用定冠词the。故选B。

我也是这个答案