The T.H.L.O is optional! I encourage you to complete them whenever possible! You will gain valuable knowledge, bonus points, and learn to be more responsible for your learning.
If you choose not to do the T.H.L.O, no penalty will be given. You will not be given a zero and points will not be deducted. The assignments are not necessary to the basic content of the next day's lesson. These opportunities are designed to enrich what you are already doing in class.
However, if you are falling behind in your own work, you will be given individulized homework assignments until you catch up!