问题补充:
— times do you visit your grandparents every year?
— Three or four times a year. Usually at Mid-Autumn festival and Spring Festival.
A. How long
B. How often
C. How much
D. How many
答案:
A. How long
B. How often
C. How much
(答案→)D. How many
解析:How long多长;How often多久一次;How much多少钱;How many多少个。根据下文,一年三到四次。可知上文提问的是频率,故选D,每年你多久拜访你的祖父母一次?