do you send an e-mail to your cousin?Sometimes.A. How long B. How muchC. How often

问题补充：

--- do you send an e-mail to your cousin?

--- Sometimes.

A. How long

B. How much

C. How often

D. How soon

答案：

A. How long

B. How much

(答案→)C. How often

D. How soon

解析：sometimes表示频率，意思是有时，故用how often来提问。