Answer:
Deep ocean currents Differences in water density, resulting from the variability of water temperature (thermo) and salinity (haline), also cause ocean currents. This process is known as thermohaline circulation.
Explanation:
A hydrometer is an instrument that measures the specific gravity (relative density) of liquids. The ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass, and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float
Lead.
"Due to insufficient water treatment, lead leached from water pipes into the drinking water, exposing over 100,000 residents to elevated lead levels."
Penicillin was made to help soldiers
