Final answer:
The best topic sentence would be: Visitors who camp in areas populated by black bears risk confrontations with bears in search of food.
Step-by-step explanation:
The best topic sentence to introduce a paragraph containing these details would be: Visitors who camp in areas populated by black bears risk confrontations with bears in search of food. This topic sentence sets the stage for the details that follow, which talk about black bears' problem-solving abilities and the precautions taken by parks to protect visitors. By mentioning the risk of confrontations with bears in search of food, the topic sentence establishes the main idea of the paragraph.
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