Where are the comets?

IF dinosaurs became extinct because a comet hit the Earth, how come comets are not hitting the Earth now? There is more than one theory about why the dinosaurs became extinct, but the giant-meteor theory is certainly one of them.

Comets tend to burn up as they enter the atmosphere, but meteors rain down all the time.

Tons of meteorites are known to fall onto the Earth each year. Some of them are quite large.

For example, in 1911, a basalt stone originally from the surface of Mars sent meteorites down on Egypt.

Part of it landed on a dog! Other famous meteorites have come from the moon, such as the Calcalong Creek meteorite in Western Australia. And in Argentina, a 33-ton meteorite was found.