题干
— ______sleep do you think is necessary for a Grade 9 student?
— 8 hours at least.
A：How often
B：How long
C：How many
D：How much
答案(点此获取答案解析）
D
— ______sleep do you think is necessary for a Grade 9 student?
— 8 hours at least.
A：How often
B：How long
C：How many
D：How much
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