Rereading and a text can readers understand difficult passages.

Paraphrasing

The question should actually appear as follows:

Rereading and a text can help readers understand difficult passages.

If a passage is difficult, what one should do is attempt to read the passage a second time.  After rereading it, one should paraphrase what was just read—retell the information in your own words.  Paraphrasing is particularly helpful because when one paraphrases, a basic understanding is fostered as paraphrasing requires one to “process” information in way that simply reading does not require.  

to inform the reader that the text will take a second look at the grimms’ original tales