Answer:
Top soil
Explanation:
It keeps all of the others below. we are able to plant and grow things on it.
..............4 is D and 6 is A
The answer is: sustained (or extended) release preparation.
<span>A sustained-release medication is a drug whose release of the active ingredient is controlled over time, that is to say, that it diffuses more slowly and longer in the body.
</span>These medications can be any type of preparation, it could be tablets, capsules, ophthalmic or dermal insert, suppository...
the correct answer is Proportional
<span>air = a mixture of nitrogen, oxygen and some other bits
(pure) CO = carbon monoxide, a compound
pure water = H2O, a compound.</span>
