What two ideas do modern writers seek to juxtapose

The is will be right depending on your class, but Making the Character(s) Relatable, and making a rough scene Emotional. I often try to do this for my psychology class.

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.