The Jeffrey Carroll step is the process you are referring to.<span />
There are about 950,000 species of insects known but estimates range as high as 2-10 million which means that there are probably many species not yet known which have probably gone undetected so far in perhaps more remote parts of the world.
The correct answer would be D
They use a hygrometer. It measures relative humidity (the amount of moisture in the air) A psychrometer is an example of a hydrometer
A little trick i learnt: The atomic number reflects how many electrons there are, and there must be an equal charge. therefore, there are the same amount of protons as there are electrons. so if it has 81 protons, we look for number 81 in the periodic table, Thallium
