Theories are a collection of scientific data that is generally accepted and reproducible. Theories are a result from several repeated experiments, but theories are not based on a single hypothesis. Several hypotheses are tested and appraised to become a well accepted theory. Theories may also be revised over time and can predict what may happen in the future. On the other hand, theories are not proven facts.
Answer:
cutting down all trees for lumber
As Earth orbits the Sun, this same principle is used by astronomers to determine the distance to nearby stars. ... Parallax is the first "inch" on the yardstick with which astronomers measure distances even further to objects.
A. objects made of crystals minerals water and air
Process of elimination-
there isn’t organic matter in rocks so D is out
they are made of minerals so B is out
some types of rock (pumice) have air bubbles in them so A is more likely than C