Answer:
the answer is A
Explanation:
Animals get thenitrogen they need by eating plants or other animals that contain nitrogen. When organisms die, their bodies decompose bringing the nitrogen into soil on land or into ocean water.
Nucleotides are the monomers in both DNA and RNA
Answer:it should be a right triangle because
12.5²+30²=32.5²
area of the triangle=

One fourth means (one half) of (one half) .
So the 18 months must be two half-lifes.
The half-life of this particular isotope is 9 months.