does your father visit your grandparents a week? –Once.A. How oftenB. How many timesC.

问题补充：

-- does your father visit your grandparents a week? –Once.

A. How often

B. How many times

C. How long

D. How soon

答案：

A. How often

(答案→)B. How many times

C. How long

D. How soon

解析：A. How often How often多久一次； B. How many times How many times多少次； C. How long多长时间；D. How soon多久，对将来的提问。联系下文一次可上文提问你爸爸一周几次看望你的爷爷奶奶，故选B.