It means every thing is made out of Atoms and some things are element componds so elements are the "backbone" of the compounds.
B. <span>much precipitation </span>
Well first of all, a planet doesn't have a semimajor axis, although it's orbit does.
In an orbit with a smaller semimajor axis, the planet moves faster, and its orbital period is shorter.
That's why the International Space Station circles the Earth in less time than the Moon does.
1.add the amount of the diagram which is M+Y then dived the answer you get.
