问题补充:
— times did you do exercise last week? — Twice.
A. How often
B. How much
C. How many
D. How long
答案:
A. How often
B. How much
(答案→)C. How many
D. How long
解析:句意:—你上周做了几次运动?—两次。A为“多久一次”,表频率;B为“多少”,后接不可数名词;C也是“多少”,后接可数名词。D为“多久”,可表时间。题中times为可数名词的复数,故选C。