Roberto wants to write a short piece to share his effective study techniques with his friends and other students. the best way to communicate his ideas would be through a(n) blog. e-book. e-zine. online reference.

A blog is the correct answer.

Explanation:

A blog is the abbreviation of "web-log", which indicates that the record of some actions (in this case Roberto's effective study techniques) are shared online. Since there is not a minimum or maximum amount of words of pages, this is the best option. An e-book must be longer than a blog entry and Roberto's experiences might not be enough to write one, and the edition process is also more complicated. If he participated in an electronic magazine (e-zine), this would also be a reliable option, but since other parameters are required (such as a periodicity and a minimum amount of pages) this is not the best way to communicate Roberto's techniques. Finally, an online reference is perhaps the least indicated option, since it is related to a library service done online.

these have to be in your own words

a compare and contrast essay is a piece of formal writing in which the author focus on the similarities between two ideas, objects, places, etc., and the differences between them. there are some aspects that the author should take into account when he/she is crafting the essay. first, the author has a clear idea of the effect that he/she wants to produce on the audience (a purpose). his/her main idea should be presented in the thesis statement in a simple but effective way which gives the audience a clear idea of the content and the direction of the essay. in addition, it is also important to focus to the similarities and differences that not only are interesting and relevant to the reader but also provide a new, impressive point of view or deeper understanding of a topic.