266. Certain pesticides can become ineffective if used …

Certain pesticides can become ineffective if used repeatedly in the same place；one reason is suggested by the finding that there are much larger populations of pesticide-degrading microbes in soils with a relatively long history of pesticide use than in soils that are free of such chemicals.

(A) Certain pesticides can become ineffective if used repeatedly in the same place；one reason is suggested by the finding that there are much larger populations of pesticide-degrading microbes in soils with a relatively long history of pesticide use than in soils that are free of such chemicals.
(B) If used repeatedly in the same place，one reason that certain pesticides can become ineffective is suggested by the finding that there are much larger populations of pesticide-degrading microbes in soils with a relatively long history of pesticide use than in soils that are free of such chemicals.
(C) If used repeatedly in the same place，one reason certain pesticides can become ineffective is suggested by the finding that much larger populations of pesticide-degrading microbes are found in soils with a relatively long history of pesticide use than those that are free of such chemicals.
(D) The finding that there are much larger populations of pesticide-degrading microbes in soils with a relatively long history of pesticide use than in soils that are free of such chemicals is suggestive of one reason, if used repeatedly in the same place, certain pesticides can become ineffective.
(E) The finding of much larger populations of pesticide-degrading microbes in soils with a relatively long history of pesticide use than in those that are free of such chemicals suggests one reason certain pesticides can become ineffective if used repeatedly in the same place.

OA: A (bôi đen để thấy đáp án)

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Nghĩa:

Certain pesticides can become ineffective if used repeatedly in the same place；

one reason is suggested by the finding that

• there are much larger populations of pesticide-degrading microbes
  • in soils with a relatively long history of pesticide use
  • than in soils that are free of such chemicals.

POE:

B) Loại vì:

• If used repeatedly … one reason: implying that “one reason is used repeatedly” => not intended meaning

C) Loại vì:

• If used repeatedly … one reason: implying that “one reason is used repeatedly” => not intended meaning

D) Loại vì:

• one reason, if used repeatedly in the same place: the green part seems to modify “one reason” => not intended meaning

E) Loại vì:

• suggests one reason certain pesticides can become ineffective: you should probably have “that” after “one reason”.
• “the finding of” is unidiomatic in this place. you need “the finding that…”
  (you might be able to use “the finding of X” for a situation in which you’re literally finding some physical object X – e.g., under the couch – but even then that would be awkward wording. in any case, that doesn’t apply here, so there’s nothing to worry about.)