The cancellation can happen within a certain scope optionally, which means you cannot use a human task to meet this requirement. Instead, you can use the event handler to meet this requirement.

取消动作可以在一定范围内随时发生，这意味着您不能使用一项人工任务来满足这个需求，而是应使用事件处理程序。

youdao

We recommend that you use this naming convention when defining event handlers for your own events, but it is not required; you can use any valid subroutine name.

建议使用此命名约定定义您自己事件的事件处理程序，但这并不是必选的方法；您可以使用任何有效的子例程名称。

youdao

Use this pattern whenever you want to find out about the timing of an event in the past, present, or future.

当你想知道过去、现在或者未来某件事发生的时间时，你都可以使用这个句型。

When 课堂 - SpeakingMax英语口语达人

Now researchers have shown for the first time that an animal other than a human can remember the social context of a past event, and use this knowledge to adjust its behaviour and plan for the future.

ECONOMIST: Ethology

In a statement on Tuesday, the Grand Orange Lodge said: "In keeping with the high ideals of the Orange Institution all members and supporters of the institution should use the eleventh of July to prepare for this event in a totally peaceful manner, " it said.

BBC: News Online

This is largely an offshoot of an event -- I use the word "event" somewhat loosely -- last year.

WHITEHOUSE: Press Briefing