--does Mary usually go to the bubby club?--Once a week.A. How muchB. How longC. How farD.

问题补充：

--does Mary usually go to the bubby club?

--Once a week.

A. How much

B. How long

C. How far

D. How often

答案：

A. How much

B. How long

C. How far

(答案→)D. How often

解析：回答语是表示频率，对频率提问的常用how often，故选D,A可以问价格，B可以问长度，C可以问路程，故选D。