do you stay at home at weekends?Ten hours.A. How oftenB. What timeC. How longD. W

问题补充：

--- do you stay at home at weekends?

--- Ten hours.

A. How often

B. What time

C. How long

D. When

答案：

A. How often

B. What time

(答案→)C. How long

D. When

解析：How often多久一次；What time什么时间；How long多长；When什么时候。根据答语，十个小时。可知上文问的时间长久，故选C。