<span>two objects in contact with each other are the same temperature</span>
It would be "Researchers found environmental safe replacements for CFC's"
Investigators are most likely to use the case history method when they study <span>a rare behavior or an unusual person.
They do this to obtain some sort of basis that they could use as a pointer to make their decision regarding the similar case (after figuring out the difference in situation between each period)</span>
