Read the text to answer numbers 1-3.

Snakes don't see or hear as well as other animals. A snake has eyes but no eyelids. They have clear scales over their eyes. Most snakes can see movement, but some snakes are blind. Snakes don't have cars. They have a bone in their heads that can sense low sounds and vibration. Snakes have a great sense of smell. A snake flicks out its forked tongue to collect scents. It doesn't mean the snake is hungry. The snake pulls its tongue in and sticks the forked tip into a place in the roof of its mouth called Jacobson's organ. This way of smelling lets the snake find other snakes as well as prey (animals it hunts for food). Pit viper, boas, and pythons have small pits on their heads that can sense heat. These pits help a snake sense when a warm-blooded animal is near.

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