wèi le / ràng / chōu xiàng / de / wù lǐ / gài niàn / gèng / róng yì / lǐ jiě / lǎo shī / yòng / zì zhì / jiào jù / yǎn shì / le / gàng gǎn / yuán lǐ

为了让抽象的物理概念更容易理解，老师用自制教具演示了杠杆原理。

To make an abstract physics concept easier to understand, the teacher used homemade teaching aids to demonstrate the principle of the lever.