问题
选择题
A Frenchman who lost his arms and legs successfully swam across the Channel, a challenge he for two years.
A．has been preparing
B．had been preparing
C．has prepared
D．prepares
答案
答案：B
这题考查现在完成进行时的用法：现在完成进行时表示过去到现在一直在进行的动作，句意是：一个失去膀子和腿的法国人成功的游过了海峡，这是他准备了两年的挑战。选B。