(i couldn't find science)
which statement about a dichotomous key is true?
1. a dichotomous key is based on the temporary actions of an organism.
2. a dichotomous key may include a question that has three or more answers.
3. a dichotomous key may have a group with no organisms in it.
4. a dichotomous key is complete when each organism stands alone.

The answers are out a and b

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.