While explaining something to others, students reinforce their own knowledge about the subject.(Para.7)

Meaning: When they explain something to others, students get a stronger and firmer understanding of what they have learned on the subject.
reinforce: vt. make stronger or firmer; add strength or support to
They hope to reinforce their idea that online learning is not easier than learning in regular classrooms. In fact, many students say it requires much more time and effort. 他们希望强调他们的观点，即网上学习不比课堂学习容易。事实上，许多学生说它需要花更多的时间和力气。