Which one event in the story almost caused them to turn back and give up?

The criteria that should be used to review a topic sentence are:

4. The topic sentence states the main idea of the paragraph.

5. The topic sentence is supported by details in the paragraph.

Explanation:

In writing, a topic sentence is a sentence that summarizes tha main idea of a paragraph. The topic sentence -or focus sentence- is usually placed at the beginning of the paragraph because it helps organize it.

Since the topic sentence basically suggests readers what the rest of the paragraph is about, the following sentences should provide more information or more detail about that sentence by offering relevant facts about it.