| 释义 |
optional /ˈɒpʃənl; NAmE ˈɑːp-/ adjective that you can choose to do or have if you want to可选择的；选修的◆You must wear a shirt and tie, but jackets are optional.你们必须穿衬衫、系领带，但是否穿夹克衫则自便。◆This model comes with a number of optional extras (= things you can choose to have but which you will have to pay extra for).这种型号有多种配件可供选购。 |