Starting at the root of the document tree and moving down to the element where the event was triggered, each element is given the opportunity to handle the event.
从文档树的根开始向下移动到触发事件的元素，其中每个元素都有机会处理该事件。
2
Are you physically healthy enough to handle the physical strains of starting and running the business?
你的身体足够健康来开始并经营辛苦的生意吗？
3
To handle this, pseudo blocks certain signals when starting a wrapper, and unblocks them at the end of the wrapper.