past perfect tense
She talked about the new job on the way to London and before long,I realized that she _15__ for my firm.I _16__ in the firm for nearly 20 years.Our boss was really a very strict man.My own secretary _17__ so I must be her new boss._18__ fair to her.
15) A had been working B will go to work C is going to work D was going to working
16) A had been working B have been working C worked D have worked
17) A was left B leaves C had left D have left
這道題的答案都是用的過去完成時,請問為什么不用現(xiàn)在完成時呢.如果說,15題用現(xiàn)在完成時表示他還是這家公司工作,但用過去完成時感覺好像已經(jīng)不在這家公司工作了?