A stop sign causes traffic to stop. We can cross the street safely because of stop signs.
Photo Credit: FatCamera/iStock/Getty Images
In the Know
National Poetry Month
April is National Poetry Month. Some United States Presidents love … read more
In the Know
Do You Play with Your Food?
Food scientists make our food safe. They study ways to … read more
In the Know
Bats Use Sound to “See”
Bats and other animals, such as whales, use echolocation to … read more