如果不能参加，你还是该送新人一份礼物。

If you cannot attend, you should still send the couple a gift.

youdao

如果你不能参加家庭庆祝活动，不要担心。

If you can't attend a family celebration, don't worry about it.

youdao

如果你不能参加会议，我会替你去。

If you can't attend the meeting, I'll go instead.

youdao

So, in terms of what it is that you need to prepare and bring with you for the exam, you need to bring your MIT ID, especially if you haven't been showing up regularly to your recitations and you aren't 100% sure if your TA knows exactly who you are, you need to make sure you have your MIT ID with you.

那么，关于你需要做哪些准备,考试可以带哪些东西，你需要带着你的学生证，尤其是如果你没有经常地参加,习题课,你不能百分之百保证,你的助教确实认识你，那么你更得确保自己到时带着学生证。

麻省理工公开课 - 化学原理课程节选