Acut (roses, rose's, roses') (petals, petal's, petals') will wilt quickly.

rose's; petals

Explanation:

This is the correct combination of words for this sentence. In the first case, the rose requires an "s" because the word represent a possessive. We are talking about a rose that has ownership of the petals. In the second case, the word "petals" requires an "s" because it is a plural form, which means it does not need an apostrophe.

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.

the answer to this question