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. 他們希望強調他們的觀點，即網上學習不比課堂學習容易。事實上，許多學生說它需要花更多的時間和力氣。