Does anyone know that I exist...

I do,and I will always know that yoy exist

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.

alliteration is the repetition of the same or similar consonants. having that in mind, i would say that the correct answer is: so shows a snowy dove trooping with crows.