Something that’s strange or doesn’t happen often
in a sentence “ in all his travels he studied only the phenomena of nature and life

Density is defined as Mass per unit volume of an object ~
And hence, the correct choice is ~ 1


Every organic molecules/compound contains carbon (c).
Some other very abundant are hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
I learned this with the acronym CHNOPS.
C - Carbon
H - Hydrogen
N - Nitrogen
O - Oxygen
P - Phosphorus
S - Sulfur
Hope this helps!
An artery carries blood away from the heart, a vein carries blood to the heart.