Earth science --the line of longitude used as the origin in a system of coordinates

prime meridian?
true north?
latitude?
longitude?
map?
reference point?
cardinal directions?

The best answer is (a) which is universal law is in effect at all times. it is constantly at play in everything we do and governs our lives. it is also important to note that universal law applies to not only everything on earth, but everything in the universe as well, which is another reason why it is in effect at all times.

An atom's smaller negative particles are at a distance from the central positive particles, so the negative particles are easier to move.