Answer:
Hippos capsize boats. They trample people. They bite to protect their young.
Step-by-step explanation:
This is the sentence that you would expect to read under the main fact 2. In this passage, we learn that the main fact 2 states that hippopotamuses have been known to cause death in many different ways. Therefore, the supporting details of the sentence should state the different ways in which these animals cause death. Some examples would be how they capsize boats, how they trample people and how they bite to protect their young.