How many hours do we usually spend in sleeping a day？
举一反三
- How many hours do you spend ____ learning English every day?
- How many hours do you spend ____ learning English every day? A: in B: out C: of D: from
- How many hours a day does George spend every day studying in college?
- How many times a day do we take temperature for the patient?（
- 中国大学MOOC: How many types of booth do we usually have ?