Question

Effective notes should include _____. every word that a speaker or writer uses main ideas of the lecture or text about 1/3 of the amount of material included in the speech or article for which you are taking notes

Answer 1

The best answe is :main ideas of the lecture or text .

It's impossible to write down every word and randomly choosing 1/3 is also not effective, it's best to write down the main ideas.