“hours do you sleep every day ?” “Nine.”A. How longB. How manyC. How muchD. How often

问题补充：

“hours do you sleep every day ?” “Nine.”

A. How long

B. How many

C. How much

D. How often

答案：

A. How long

(答案→)B. How many

C. How much

D. How often

解析：A. 多久，多长 B. 多少，后接可数名词复数 C. 多少，后接不可数名词 D. 多久一次。根据下文九个。可知前文提问的是数量，hours为名词复数，故选B。