Misc: the snake river winds through which gorge?

Questions

It takes about 50 hours for a snake to digest one ----------?

There are about 5,000 species of ---------- known. Only about half of them build reefs.?

The Mola Mola, or Ocean Sunfish, lays up to ---------- eggs at one time.?

The crocodile is a cannibal; it will occasionally eat other ----------?

Researchers don't know why killer whales like to rub their sensitive stomachs on the bottom of shallow beaches, but they think it may be a form of ----------?