In the United States, cell phones are a very popular item.
What is the verb

are

Explanation:

since cellphones is the subject, what the subjects are or are doing is "are."

no verb foolish studies

A. Details to include in summary

1. Evidence shows that the  mountains were inhabited  over 10,000 years ago.

2. The people who lived in the  mountains were hunter- gatherers .

3. Spaniards came to the  mountains in the mid  sixteenth century.

B. Details to omit from summary

1. Many of the early residents  lived in caves.

2. Ancient pottery and rock  art have been found in  the mountains.

Explanation:

A summary is a comprehensive account or statement that covers the main points of an event or a story.  It omits unnecessary details while keeping others that make the account to be understood.  It is the elimination of irrelevant details and examples that make an account to be a good summary.  It is a concise and brief rewriting of a report in the words of the writer to reflect his or her personal understanding of the main ideas.