I need help for my research paper

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Have you written down the points you want your paper to cover?

There are approximately 27,900 gangs, with 774,000 members, impacting towns, cities, and communities across the United States. Gang violence is the largest issue in the united states.
And yes why there is gang violence,impact and prevention

What about this? And we need more?

As of this year, there are approximately 27,900 gangs in the United States, with 774,000 members, that impact cities, towns, and even rural communities. Gang activity hinders society's ability to function in a peaceful and productive way. Why is there gang violence, how does it impact our daily lives, and how can it be prevented?

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From csun.edu --

The thesis statement is best seen as a single, complete sentence containing the main idea of the entire composition with at least three (3) patterns by which you intend to develop and support that subject. You could not write a very good or insightful essay, for example, if your thesis was “The Hyundai is a great car.” That statement by itself is both vague and general. It has no focus and fails to give the audience anything in terms of where the composition is going. On the other hand, the audience receives a clear sense of direction from a thesis statement that reads “Because of its great gas mileage, low maintenance, and outstanding road handling on highways and city streets, the Hyundai is a great car.”

From this thesis statement, we know that you are going to write about (1) the great gas mileage a Hyundai gets in comparison to other cars, (2) the low maintenance and monies saved in repairs with the Hyundai in contrast to other vehicles, and (3) the responsive way the Hyundai handles on the road in relationship to other cars on the highways and city streets. Those three patterns of development all contribute to and support the main idea, which is that the Hyundai is a great car. They do so in a logical, orderly fashion which is what your readership expects in a well-organized composition.