Answer:
Running water is the leading cause of soil erosion, because water is abundant and has a lot of power. Wind is also a leading cause of soil erosion because wind can pick up soil and blow it far away. Activities that remove vegetation, disturb the ground, or allow the ground to dry are activities that increase erosion.
Https://www.reference.com/science/plant-cells-bigger-vacuoles-animal-cells-6ce1d958f161267a#
This site has a very complete answer that is very thorough.
The only way to send information back and forth is to use radio waves. Just like a radio station broadcasts a signal which you can listen to using a radio, astronauts and people on Earth can broadcast information back and forth to each other.
Radio waves are transverse waves.
One reason would be the increased chance of Down syndrome