What is a galaxy?
OPTIONS:
- a moon that orbits a planet
- a planet that orbits the Sun
- a very large system of stars that is held together by gravity
- a very large system of planets that is held together by the Sun

a very large system of stars that is held together by gravity

At a weightlifting competition, two competitors lifted the same weight to the same height. The second competitor accomplished the lift 2 seconds faster than the first competitor. This demonstrated that the second competitor had more
OPTIONS:
- energy than the first.
- inertia than the first.
- power than the first.
- work than the first.

power than the first.

Which of the following identifies the primary function of a radio station tower in a communication system?
OPTIONS:
- decoder
- encoder
- receiver
- transmitter
transmitter