Question 20 　Outside classroom hours, how long do you usually study for each session of this course? (the study time includes preparing for each session, reviewing the course materials after class, completing assignments, preparing for presentations, discussing related topics with your instructor/classmate outside classroom, researching related topics when commuting, etc.) ①Less than 30 minutes　②30 minutes to 59 minutes　③1 hours to 1 hours and 59 minutes　④2 hours to 2 hours and 59 minutes　⑤More than 3hours