shí yàn kè shàng / lǎo shī / ràng / wǒ men / yòng / āo tòu jìng / guān chá / píng xíng guāng xiàn / de / fā sàn xiàn xiàng

实验课上，老师让我们用凹透镜观察平行光线的发散现象。

In the lab class, the teacher asked us to use a concave lens to observe how parallel rays diverge.