Answer:
Explanation: Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device preserves the input power and simply trades off forces against movement to obtain a desired amplification in the output force.
Answer:
Salt in the ocean comes from two sources: runoff from the land and openings in the seafloor. Rocks on land are the major source of salts dissolved in seawater. Rainwater that falls on land is slightly acidic, so it erodes rocks.
The correct answer is B, widespread pollution. If you look closely, you can see that the other answers are not problems at all, but benefits! :)
