I had meant to meet you at the airport this morning but I was too busy for I a report.A.

问题补充：

I had meant to meet you at the airport this morning but I was too busy for I a report.

A. wrote

B. was writing

C. have written

D. had written

答案：

A. wrote

(答案→)B. was writing

C. have written

D. had written

解析：B 考察动词时态。句意：我本打算今天早上去机场接你，但我太忙了，因为我正在写一份报告。根据句意和句中时态可知，此处表示今天早上本该接你的时候我正在写一份报告。即过去某一时刻或某一阶段正在进行孩子发生的动作，因此应该使用过去进行时。故B正确。