Why were you so late for work today？ to the office was very slow this morning beca

问题补充：

--- Why were you so late for work today？

--- to the office was very slow this morning because of the traffic.

ADriving

B. I drove

C. To drive

D. That I drove

答案：

(答案→)A. Driving

B. I drove

C. To drive

D. That I drove

解析：考查动名词做主语用法。本题中的动名词driving to the office做为句子的主语，动名词做主语指经常性，习惯性的行为。B项不能做主语；C项不定式做主语是指一次性的行为；D项是主语从句做主语，但是意思不句意不配。句意：—为什么你今天迟到了？—因为交通高峰期，所以驾车去办公室里很慢的。故A正确。