If you know in advance that the lecture you are going to attend will probably be boring because of it being a review, it is very important to sit as far back as possible. You do not want the teacher to be able to see you and the fact that you are not paying attention.
If you have your laptop, then playing games is a great way to stay entertained and look like you are working at the same time. Make sure that you keep the laptop on mute so that the sound does not distract the other students or let the teacher know that you are playing games instead of working like you should be.
Instead of wasting time with other things, it is important to focus on completing any other tasks and homework you may have at hand. Most students always do have something else that they can work on and this is a good time to do so. Instead of having to focus on something you already know, trying getting to that point where you are able to cover something that you are still not that familiar with.
Making new contacts is always a good idea, especially during your years at school. Networking is always important and strengthening those relationships is an even better one. So the next time you are bored out of your mind, try making some new friends or even getting in touch with those who you have not for quite a while.
Whether it is a text book or your favourite novel, reading is a great way to build your vocabulary, imagination and staying entertained. Make sure that it is not anything that may offend someone else and should be kept under the table.