Which of the following BEST explains why using chemical fertilizers and pesticides is harmful to the soil?
Nutrients cannot replenish if there is a chemical presence in the soil.
Plants usually die when exposed to chemical fertilizers and pesticides.
Chemicals introduced to the soil can change its nutrient and content levels.
Chemicals present usually means that the soil is already depleted of nutrients.

What would a student most likely use if he or she wanted to consult a secondary source

“dear sir: it is with great reluctance, i trouble you on a subject, which does not fall within your province; but it is a subject that occasions me more distress, than i have felt, since the commencement of the war; and which loudly demands the most zealous exertions of every person of weight and authority, who is interested in the success of our affairs. i mean the present dreadful situation of the army for want of provisions, and the miserable prospects before us, with respect to futurity. it is more alarming than you will probably conceive, for, to form a just idea, it were necessary to be on the spot. for some days past, there has been little less, than a famine in camp. a part of the army has been a week, without any kind of flesh, and the rest for three or four days. naked and starving as they are, we cannot enough admire the incomparable patience and fidelity of the soldiery, that they have not been ere this excited by their sufferings, to a general mutiny or dispersion. strong symptoms, however, discontent have appeared in particular instances; and nothing but the most acitive efforts every where can long avert so shocking a catastrophe.” what’s the central idea?

Which is relatively better: a score of 76 on a psychology test or a score of 22 on an economics test? scores on the psychology test have a mean of 90 and a standard deviation of 13. scores on the economics test have a mean of 52 and a standard deviation of 10.