Can someone answer this?

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.

first of all wood chucks don't "chuck" wood. none, and for the fun of the answer the amount of wood chucked would be a lot!

explanation:

a wood chuck is a ground hog, it belongs to the family of large underground squirrels. it belongs to the family of marmots. ground hogs eat grasses, berry's, and other vegetation.