Read the text again and listen. Circle the correct answer a, b, or c.1. The writer mentions bees and dogs... a. because they want to learn how they communicate.
b. as examples of animal communication. c. because they use infrasonic communication.

2. Humans can hear ...
a lower sounds than elephants can.
b. sounds that travel long distances.
c. sounds with higher pitch.

3. Things like trees.
a. cause problems for low sounds.
b. cause problems for high sounds.
c. don't affect sounds at all.

4. In places like zoos...
a. humans can sense when infrasonic sounds are being made.
b. elephants don't need to make infrasonic sounds.
c. it is easier than in wildlife parks to sense when elephants use infrasonic sounds.​