他们每天花半小时锻炼 They spend half an hour ____ ____ ____ every day.
问题描述:
他们每天花半小时锻炼 They spend half an hour ____ ____ ____ every day.
答
in doing exercise
他们每天花半小时锻炼 They spend half an hour ____ ____ ____ every day.
in doing exercise