Jonah is learning about electromagnetic and mechanical waves in school. He writes a list comparing both types of waves. The table shows his list. Waves
Only electromagnetic waves can travel through solids.
Only mechanical waves need to travel through a medium.
Both types of waves can can travel at different speeds.
Both types of waves transmit energy over long distances.

Jonah made a mistake in his list. What mistake did he make, and what should he write to correct his mistake?