For the first blank it would be: Lock
&
For the second blank it would be: Key
Well, the asthenosphere is located in the upper mantle. So that is how they are related.
Answer:
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth.
Explanation:
2 - Human refuse to stop polluting.
All other three are attempting to attack the problem of pollution.
