Answer:

For a supplement to instruction, Text materials might possibly be the one to get hold of worksheets, study guides, and printed modules in conjunctions with video/voice technologies. It is also important to note that supplemental print materials could be distributed via mail or internet. Additionally, Fax Machines could be used to transmit the printed materials back and forth to the students and teachers. With those materials, students now has control on their study hours, Nevertheless, there are some drawbacks in incorporating printed materials.

This took a lot of time to paraphrase, hope it helps!

(ps sorry if theres any wrong spelling or grammar.)