| 释义 |
op.tion.alH5Bp7F[n7[l, $5B:p-adj [not gradable]If something is optional, you can choose whether to do it, pay it, buy it, etc..可选择的English, maths and science are compulsory for all students, but art and music are optional. 英语、数学和科学所有的学生都必须学，但是艺术和音乐是可选择的。The charge for going into the museum is optional.进这座博物馆的费用不是必须付的。The computer comes with a number of optional accessories.这台计算机配有很多任选的附件。
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