Read the paragraph from The Hot Zone. Just then, he noticed a blur of motion on his left, and he turned and saw two Hazleton workers walking toward him. They weren't supposed to be in here! The area was supposed to be sealed off, but they had come in by another route that led through a storeroom. They wore respirators, but nothing covered their eyes. When they saw the two men in space suits, they froze, speechless. Jerry could not see their mouths, but he could see their eyes, wide with astonishment. It was as if they had suddenly discovered that they were standing on the moon. What is the author’s main purpose for including this paragraph?