有的英语的时态考题特别注重利用题干本身所提供的语境进行考查。如果考生在做题时，只顾理解填空处的句意，而忽略对上下文语境的连贯理解，则可能步入命题人设计的陷阱。如：
■ I was giving a talk to a large group of people, the same talk I _______ to half a dozen other groups. (湖南卷)
A. was giving B. am giving C. had given D. have given
许多同学可能会简单地根据前面的was giving而误选A。但事实上，此题提供的语境是：我当时正在给一群人作报告，这个报告我曾给其他若干批人讲过。由于was giving为过去进行时，而“曾给其他若干批人讲过”显然发生在was giving这一过去时间之前，故用过去完成时，即答案为C。
■ Father _______ for London on business upon my arrival, so I didn’t see him. (福建卷)
A. has left B. left C. was leaving D. had left
若单独看Father _______ for London on business upon my arrival这一句，则答案为C或D均可。但是，若结合后面的so I didn’t see him，则答案只能选D。因为，既然“我没有见到他”用了过去时态，那么“父亲离开”就肯定属于“过去的过去”，故要用过去完成时。
From: http://www.hxen.com/grammar/yufalianxi/2011-07-28/150540.html