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题目材料：
Insect predators usually keep the number of aphids in crop fields low. However, sometimes the aphid population explodes in size, causing major damage. Such explosions happen when unusually cold weather keeps the number of aphids low in the spring. One possible explanation is that, with fewer aphids to feed on, the predator population also drops, and in summer when the aphid population starts to grow there are not enough predators to keep it in check.
Which of the following, if true, would most strengthen the explanation given tor aphid population explosions?
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AWhen a pesticide that affects both aphids and aphid predators is applied to a field, once the pesticide washes away there is an aphid population explosion.
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BInsect predators of aphids can survive for long periods without food as long as the weather remains cold.
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CWhen weather is unusually cold in the spring, certain crops are more abundantly in the following summer, increasing the supply for aphids.
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DThe predators of aphids can die from causes other than such as disease and severe weather.
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EAphids can produce very quickly if they have sufficient food.
E显示答案
