Ques:Q: What thin layer of air acts as a barrier to prevent cool air from mixing with warm air in the stratosphere? Choices: - methosphere - endosphere - liposphere - tropopause A:

Ans:tropopause
-----
Ques:Q: What process brings nutrients from the ocean's floor to its surface? Choices: - Down welling - coastal swell - Tides - upwelling A:

Ans:upwelling
-----
Ques:Q: What is used to fluoridate drinking water to promote dental health Choices: - carbon fluoride - calcium fluorine - carbon fluorine - calcium fluoride A:

Ans:calcium fluoride
-----
Ques:Q: What term means the amount of a substance required to form a saturated solution in a given amount of solvent at a specified temperature? Choices: - viscosity - concentration - turbidity - solubility A:

Ans:
solubility
-----