D is not correctly describe a rock
Adenine always pairs with Thymine. (DNA)
Guanine always pairs with Cytosine.
(DNA)
*In the (RNA) Adenine pairs with Uracil (U).
-A and T
-C and G
-T and A
-G and C
-G and C
-G and C
-T and A
-A and T
-C and G
-T and A
A proposal Intend to explain certainly facts or observation
Ecosystems experience change through human activity and natural events. This is because human activity can impact changes in nature, like climate for example. As a result, ecosystems change in response to the change in nature or natural events, which was caused by human activities. They are interrelated so to speak.