come up的用法和短語

　　We'll let you know if any vacancies come up.

　　一有空缺，我們就會通知你。

　　It will be so great watching the sun come up.

　　看著太陽升起將會很美妙。

　　The question is bound to come up at the meeting.

　　會上一定會討論這個問題。