Liquid 1 and 4, because they have the same melting point and density.
Answer:
Gravitational forces.
Explanation:
The same reason the earth revolves around the sun, its all thanks to gravity!
-I hope this answers your question!
Pros (good):
- Inexpensive
- Can degrade the crudest oils
- Quick and minor waste is water and CO2
Cons (bad)
- Waves can carry bacteria into place they are not needed or wanted
- Germs may harm marie animals by putting excess CO2 in water
- Germs may be harder to exterminate because they are engineered
Cells defend themselves from viruses, bacteria with armor of protein errors