Cách sử dụng
A reef is a kind of underwater ridge or rock formation that is found in oceans, seas, or other bodies of water. Some reefs are close to the surface and visible, while others may be hiding just below the water's surface. Reefs can be dangerous for boats and ships, and many are home to a wide variety of sea creatures, such as fish, turtles, and coral. They're often popular spots for scuba divers and snorkelers to explore. When using the word "reef," you might talk about a specific reef that you have visited or admired, or you might use the term more broadly to talk about the ecology and environment of reefs in general.