How are Mercury and Earth's moon similar?

They both have the same rotation speed.
They both have very smooth surfaces.
They both lack atmospheres.
They both have active volcanoes.

The study of interaction between living organisms and their enviroment is called (a) phytogeography (b) ecology (c) phytosociology (d) ecosystem

This is a typical grassland food web. it is also a small picture of an important cycle on earth: the carbon cycle. describe how the carbon gets into this food web. a) bacteria and fungi, the decomposers, recycle carbon from dead organisms. b) carbon is found in the grass and is passed from one level to the next in this food web. eliminate c) all living things give off carbon dioxide as a by-product of respiration and it is released into the atmosphere. d) plants use carbon dioxide as a reactant in photosynthesis, to make usable chemical energy in the form of a sugar.

Which step is not included in the step approach to calculating the greatest common divisor?