— do you water the flowers?—Twice a day.A. How manyB. How many timesC. How oftenD. How soo

问题补充：

— do you water the flowers?—Twice a day.

A. How many

B. How many times

C. How often

D. How soon

答案：

A. How many

B. How many times

(答案→)C. How often

D. How soon

解析：How many多少个；How many times多少次；How often 多久一次；How soon多久。根据下文，一天两次。可知上文问的是，你多久浇一次花？故选C。