The position of the diver is described as "below a certain point"; therefore, the reference point must be above the diver. For a diver in the middle of his dive, the bottom of the pool, the other swimmers and the far side of the swimming pool are likely to be below the diver, or at level with the diver at most. Out of the options, the only point of reference that is likely to be above the diver is B. the diving board.
The answer is <span>insect and pest populations decreased.
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DDT (dichlorodiphenyltrichloroethane) was used as an insecticide which is a substance used to kill insects. That resulted in decrease in insect and pest populations. It is a persistent and non-degradable insecticide, but as well organic pollutant readily accumulated to soils and consequently affects organisms.
<span>Abiotic = Nonliving
Plants are living, they are biotic factors</span>
