---Can you tell me how often he practices his English?
--- .
A. At times
B. At one time
C. At all times
D. At a time
网友回答
(答案→)A. At times
B. At one time
C. At all times
D. At a time
解析：考查介词短语：A. At times有时，B. At one time曾经，一度，C. At all times一直，D. At a time一次，句意：--你能告诉我他多长时间练一次英语吗？--有时。选A。