Crabs eat decaying matter, thereby helping to clean up the ocean.
In nature, predators generally prey on the young, sick or weak in a group, thereby keeping the species as a whole strong and healthy.
One way to minimize a hang-over is to drink a couple of glasses of water after each
alcoholic drink, thereby preventing dehydration.
The huge fast-food chains generally pay their workers low wages, thereby helping to depress wages for workers in the entire trade.
The Japanese monster Godzilla can fly by firing a blast of energy from his mouth, thereby projecting
himself backwards through space.
Combining several errands into one trip can help you reduce the amount of gas you use, thereby helping you to reduce air pollution.
Solon, the ruler of Attica (639-559 B.C.), made it illegal to export figs out of Greece, thereby making sure there were plenty
for his citizens.
Eric Clapton has been able to adapt himself to the changing fashions of rock music, and thereby remain consistently popular.
In 1735, a New York editor was acquitted of libel, thereby establishing the concept of freedom of the press.
Martin Luther King once said that to accept passively an unjust system is to cooperate with that system; thereby the oppressed become the oppressor.
Mozart once remarked that music, even in situations of the greatest horror, should never be painful to the ear but should flatter and charm it, and thereby always remain music.
William Shakespeare wrote, "And so, from hour to hour we ripe and ripe, and then from hour to hour we rot and rot, and thereby hangs a tale."
In 1976, he won the gold medal in the Olympics, thereby achieving his greatest goal in sport.
Recent research shows that hurricanes spur the growth of plankton in our oceans by stirring up the water, thereby bringing food and plankton to the surface where sunlight allows these tiny plants to bloom.
A bat uses an echo system, whereby it sends out a sound which strikes a target, and then bounces back to the bat, thereby letting it know what lies ahead.
Predators have a beneficial effect on the health of their prey, in that they often eat the old or diseased animals, thereby keeping the species strong.