Answer:
On the basis of the temperature data he collected from different weather stations set up by the Tsar, Humboldt constructed the first world map of average temperature in which he used lines to connect points of equal temperature, called isotherms
Explanation:
This just a little search on Wikipedia it might help you
Sample of many kinds of living things should be examined under a microscope to determine the presence of cells.
Cells are the smallest unit that can be considered alive.
