practice

1. Write something.
2. Write something else.
3. Write something different.
4. Write something completely different.

numerical

1. Bats use echolocation to visualize their world. They send out ultrasonic squeaks from their little bat mouths and then listen for the echos with their giant bat ears. The characteristics of the echo will vary depending on the characteristics of the object reflecting the squeak.
   1. How will the echo from a large object (like a tree trunk) compare to a small one (like a tasty insect)?
   2. How will the echo from an object moving away from the bat (like an escaping insect) compare to one from an object moving toward the bat (like an insect about to become lunch)?