______ from endless homework on weekends, the students now find their own activities, such as taking a ride together to watch the sunrise.

单项选择题Thank you for sending us ______ fresh vegetables of many kinds. You have done us ______ great service.

单项选择题I think you've got to the point ______ a change is needed, otherwise you'll fail.

单项选择题—When did it begin to snow —It started ______ the night.

单项选择题1918年出版的教育史上第一本课程理论专著，标志着课程作为专门研究领域的诞生，其作者是( )。

单项选择题教育科学研究起源于( )。