zài / shù / xué / kè / shàng / lǎo / shī / jiǎng / jiě / le / yǎng / jiǎo / hé / fǔ / jiǎo / de / qū / bié在数学课上,老师讲解了仰角和俯角的区别。In math class, the teacher explained the difference between the angle of elevation and the angle of depression.