[, ]a series of lessons on a particular subject （某科目的）系列课程◆The institute holds classes in/on accounting throughout the year. 学院全年开设会计课程。SYNcourse ⨁to attend / go to / take classes 上课⨁to have / hold / offer / teach a class 授课
[] one of the groups of people in a society that are thought of as being at the same social or economic level 阶级；阶层◆The new taxes will hurt all classes of society. 新税收会损害社会上所有阶层。◆the professional classes 专业阶层
[] a group of things that have similar characteristics or qualities 种类；等级◆The painkiller is part of a new class of drugs. 这款止痛药是一类新型药品。◆It's the best computer available in its class. 这是该档次中现有最好的计算机。
[] each of several different levels of comfort that are available to travellers in a plane, etc. （飞机等的）舱位等级
best in class business class economy class first class second class