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  3. Ragwort was accidentally introduced to New Zealand in the late nineteenth centur

Ragwort was accidentally introduced to New Zealand in the late nineteenth centur

游客2024-01-11  57
问题 Ragwort was accidentally introduced to New Zealand in the late nineteenth century and, like so many invading foreign species, quickly became a pest. By the 1920s, the weed was rampant. What made matters worse was that its proliferation coincided with sweeping changes in agriculture and a massive shift from sheep farming to dairying. Ragwort contains a battery of toxic and resilient alkaloids: even honey made from its flowers contains the poison in dilute form. Livestock generally avoid grazing where ragwort is growing, but they will do so once it displaces grass and clover in their pasture. Though sheep can eat it for months before showing any signs of illness, if cattle eat it they sicken quickly, and fatality can even result. [br] The passage suggests that the proliferation of ragwort was particularly ill-timed because it
选项 A、coincided with and exacerbated a decline in agriculture
B、took place in conditions that enabled the ragwort to spread faster than it otherwise would have done
C、led to an increase in the amount of toxic compounds contained in the plants
D、prevented people from producing honey that could be eaten safely
E、had consequences for livestock that were more dramatic than they otherwise would have been
答案 E
解析 The passage mentions that ragwort s impact on New Zealand’s agriculture was especially severe because the plant s proliferation "coincided with sweeping changes in agriculture that saw a massive shift from sheep farming to dairying." The severity of the impact was increased because cattle, which were displacing sheep, are much more sensitive than sheep to the toxins contained in ragwort. This points to Choice E as the correct answer choice. Nothing in the passage suggests that the proliferation of ragwort coincided with a decline in agriculture(Choice A), occurred faster than it might have done(Choice B), or made the plants more toxic(Choice C). There is a suggestion that ragwort honey might not be safe for humans, but there is no indication that this made the timing of the proliferation particularly unfortunate.
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