木木 最后更新时间：2025-07-05 00:40:52
optional中文解释
adj,可选择的，随意的,同近
three optional courses.三门选修课
可选择的，随意的英释adjadjif something is optional, you do not have to do it or use it, but you can choose to if you want to
optional course,选修课，选修课程.短语
