The truth Sir is that the old man across the street when my car hit him.A. was to walkB

问题补充：

The truth, Sir, is that the old man across the street when my car hit him.

A. was to walk

B. had been walking

C. walked

D. was walking

答案：

A. was to walk

B. had been walking

C. walked

(答案→)D. was walking

解析：该题考查时态。表语从句中的主句用进行时态，从句由when引导表“突然发生意料不到的变化”。