optional
英 [ˈɒpʃənl]
美 [ˈɑːpʃənl]
adj. 可选择的; 选修的
高考CET4CET6考研TOEFLIELTSGRETEM4TEM8化学
Collins.1 / BNC.5815 / COCA.5692
牛津词典
adj.
- 可选择的;选修的
that you can choose to do or have if you want to- Certain courses are compulsory, others are optional.
某些课程是必修的,其他是选修的。 - This model comes with a number of optional extras (= things you can choose to have but which you will have to pay extra for) .
这一型号有一系列可供选择的附件,价格另计。
- Certain courses are compulsory, others are optional.
柯林斯词典
- ADJ 可选择的;非强制的
If something isoptional, you can choose whether or not you do it or have it.- A holiday isn't an optional extra. In this stressful, frantic world it's a must...
休假并非可有可无。在这个紧张而忙碌的世界,它是必不可少的。 - Sex education is a sensitive area for some parents, and thus it should remain optional.
性教育对某些家长而言是个敏感领域,因此应该保持其非强制性。
- A holiday isn't an optional extra. In this stressful, frantic world it's a must...
英英释义
adj
- possible but not necessary
双语例句
- Note that both the dependencies and the instructions are optional; only the target and the colon are required.
请注意依赖性和指令都是可选的;只有目标和冒号才是必须的。 - An activity can also have optional and required inputs and attributes, as defined by the activity's creator.
活动还可以拥有可选和必要输入和属性,这由活动创建者定义。 - This contains a list of mandatory and optional fields.
它包含一个强制性和非强制性命令的列表。 - The square brackets ( [ and]) enclose optional parameters.
方括号([和])中的是可选参数。 - Optional and named arguments can be used not only with methods but also with indexers and constructors.
可选参数和命名参数不仅可以用在方法调用中,还可以用在索引器和构造器中。 - Actions and predicate are optional.
动作和断言是可选的。 - You pass the before method an optional symbol and a code block.
您向before方法传递一个可选的标志和一个代码块。 - The cycles are periodic and optional.
循环是阶段性和可选择的。 - Above the communication protocols are the optional file attachment and security layers that are implemented with MIME.
通信协议的上面是可选的文件附件和安全层,用MIME实现。 - Our attendance at graduation is optional.
毕业典礼可以自愿参加。
