Question

the main, or central, idea of the passage is fevers are useful because they help the body fight infections. how does the detail in bold develop the main idea? fevers can be uncomfortable, but the upside is that they are evidence of the bodys attempt to heal. when a person develops an infection, a section of the brain called the hypothalamus recognizes a threat. the hypothalamus responds by increasing the bodys temperature. since both viruses and bacteria are temperature sensitive, this environment helps prevent them from multiplying. in addition, scientists have found evidence that fevers may increase the number of certain lymphocytes - white blood cells that are part of the immune system. increased lymphocytes make the body more effective in destroying infected cells. of course, this doesnt mean that high fevers dont warrant medical treatment. in fact, another reason that fevers are beneficial is that they serve as warning signs, indicating that something is amiss. it points out weakness of the fever response. it explains the function of lymphocytes in great detail. it describes one manner in which fevers fight infections.

Explanation:

The bold - faced detail talks about how fevers increase the number of lymphocytes which are part of the immune system and make the body more effective at destroying infected cells, thus showing a way fevers fight infections.

Answer:

It describes one manner in which fevers fight infections.