—How long have you been going to work on foot?—Since last month when I from a heart attac

问题补充：

—How long have you been going to work on foot?

—Since last month when I from a heart attack.

A. recovered

B. have recovered

C. was recovering

D. would recover

答案：

(答案→)A. recovered

B. have recovered

C. was recovering

D. would recover

解析：A 考察动词时态。句义：你步行上班已经多长时间了？—自上个月我心脏病康复开始。Last month是时间点，应该与过去时连用。故A正确。