Review
"the process of  going over a subject again in study or recitation in order to fix it in the memory ... "
(From The Random House College Dictionary)

I expect people attending the reviews to be somewhat familiar with the material we have been covering over the past 2 or 3 weeks.

If you have been attending class fairly regularly or
If you haven't been attending class but have been keeping up via the online notes or
If you took advantage of the extra office hours last week or
If you have used the study guide to begin to prepare for this week's quiz,

then you're WELCOME at one or both of the reviews this week.

If you have done nothing during the past 2 or 3 weeks,
have no idea what topics we've been covering,
and were planning to make the review the 1st step in a last minute effort to pass this week's quiz,

then you're welcome to first spend this afternoon or evening having a look at the material and will then be WELCOME at tomorrow's review.