I believe the answer would be <span>D.) Abnormal</span>
I believe it is D) heliocentric !
The highest point the medium rises to and a trough is the lowest point the medium sinks to.
Biological structures like DNA, proteins and cells all depend on molecules. ... Neurotransmitters like epinephrine are pretty simple molecules, but without them our nervous system couldn't work. Oxygen, containing just two oxygen atoms, is a very simple molecule, and it is certainly essential to living things.
