<span>An instrument used to measure the amount of knowledge a person has learned in a given subject or area is an Achievement </span>Test.
There’s a scientific reason why it’s smart to pack that extra sweater when you’re headed to the mountains. Temperatures drop steadily as altitude increases, at least in the first layer of atmosphere known as the troposphere. Temperature readings in the atmosphere’s other three layers, which are beyond the reach of any mountain peak, also change with increasing altitude, but they change at significantly different rates, and they don't always decrease.
