For a scientific theory to be valid, which of the following must be true?

a. it must be well tested.
b. it must be widely accepted.
c. it must explain the observable facts.
d. all of the above

explain

What is a compass? how does it work

How would i answer this for an exam?

The diagram shows , , and . which statement can be proven true from the diagram? a. ∠dgb is supplementary to ∠ega. b. ∠dgb is supplementary to ∠cgb. c. ∠cgb is supplementary to ∠agd. d. ∠ega is supplementary to ∠egc. e. ∠egd is supplementary to ∠cgb.