What is the main idea of the selection? A. how Aztec cities were built
B. how Spanish customs began
C. how two kings met each other D. how two civilizations blended

Rewrite the passage to improve expression.

Which statement best paraphrase the first line in the prologue

If an atom has no charge, what can we say about the subatomic particles in the atom? a) there will be the same number of protons and neutrons, but a different number of electrons. b) there will be the same number of electrons and neutrons, but a different number of protons. c) there will be the same number of protons and electrons.