-do you visit you grandparents ?--Once a week .AHow longBHow farCHow soonD

问题补充：

---- do you visit you grandparents ? ----Once a week .

AHow long

BHow far

CHow soon

DHow often

答案：

A. How long

B. How far

C. How soon

D. How often

解析：How long多久；How far多远；How soon多快（九）；How often（多久一次）。原句意思是：你多久去看望一次爷爷奶奶？每星期一次。根据回答，可知答案是A。