Final answer:
A flyer that describes the problem and possible solutions is the best form of writing to persuade neighbors to help solve the problem of trash in the streets.
Step-by-step explanation:
The most appropriate form of writing to persuade neighbors to help solve the problem of trash in the streets would be a flyer that describes the problem and possible solutions. A flyer is a concise and visually appealing medium that can quickly capture the attention of neighbors. It can include relevant details and visuals to convey the urgency of the issue and the benefits of taking action. For example, the flyer can include statistics about the amount of trash in the streets, the impact on the environment and public health, and specific steps neighbors can take to help solve the problem, such as organizing neighborhood cleanup events or properly disposing of their trash. The language used in the flyer should be positive and persuasive, emphasizing the collective responsibility and the positive outcomes that can be achieved when neighbors work together.