Criteria and Limitations: In this section, please list at least three criteria that must be met by your train design. Also include any limitations that could prevent it from getting its cargo to the station.

Criteria
1.
2.
3.
Limitations
1.
2.
3.

How is it possible for someone to put an ear to a wall and hear someone in the next room?     a.sound waves can travel though solids.    b.the waves travel from room to room via air.    c.there must be some air in the wall so the sound can travel through it.    d.sound waves change to electromagnetic waves and then back again.