OG8 阅读 Q43

Choice C is the best answer. The first paragraph discusses the challenge posed to the Venus flytrap by the opening and closing of its trap: "Closing its trap requires a huge expense of energy, and reopening the trap can take several hours, so Dionaea only wants to spring closed when it's sure that the dawdling insect visiting its surface is large enough to be worth its time." Since closing and reopening the trap requires the expense of precious energy, it can be inferred that by guarding against unnecessary closing, multiple triggers safeguard the plant's energy supply.
Choice A is incorrect because the passage never indicates that multiple triggers allow the Venus flytrap to identify which species its prey belongs to, only that they allow it to gauge the prey's size. Choice B is incorrect because although the passage implies that the plant needs to conserve energy and indicates that calcium is involved in the trap-closing mechanism, there is no indication that the plant's calcium reserves themselves require conservation. Choice D is incorrect because it can be inferred from the passage that the advantage of multiple triggers is that they prevent the Venus flytrap from closing on the improper prey rather than from prematurely closing on the proper prey; the passage never implies that when touched by its proper prey, the Venus flytrap is at risk of closing too soon to capture it.