问题补充:
--dose it take to get to the airport from here ?
-- It takes half an hour.
A. How long
B. How soon
C. How far
D. How often
答案:
(答案→)A. How long
B. How soon
C. How far
D. How often
解析:How long多长;How soon多久;How far多远;How often多久一次。根据答语,用了半个小时。可知上文问的是时间长短,故选A。