Turtles have an unfortunate habit of eating plastic objects floating in the sea. These then get trapped in their alimentary cana

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问题     Turtles have an unfortunate habit of eating plastic objects floating in the sea. These then get trapped in their alimentary canals, cannot be broken down by the animals’ digestive enzymes and may ultimately kill them. It is widely assumed that this liking for plastics is a matter of mistaken identity. Drifting plastic bags, for instance, look similar to jellyfish, which many types of turtles love to eat. Yet lots of plastic objects that end up inside turtles have no resemblance to jellyfish. Joseph Pfaller of the University of Florida therefore suspects that something more complicated is going on. As he writes in Current Biology, he thinks that the smell of marine micro-organisms which colonize floating plastic objects induces turtles to feed.
    The idea that the smell of plastic rubbish might lure animals to their doom first emerged in 2016. Researchers at the University of California, Davis, noticed that certain chemicals, which are released into the air by micro-organism-colonized plastics, are those which many seabirds sniff to track down food. These chemicals mark good places to hunt because they indicate an abundance of the bacteria that lie at the bottom of marine food chains. The researchers also found that birds which pursue their food in this way are five or six times more likely to eat plastic than those which do not.
    Since turtles are known to break the surface periodically and sniff the air when navigating towards their feeding areas, Dr. Pfaller theorized that they are following these same chemicals, and are likewise fooled into thinking that floating plastic objects are edible.
    To test that idea, he and his colleagues set up an experiment involving loggerhead turtles, a species frequently killed by plastic. They arranged for 15 of the animals, each around five months old, to be exposed, in random order, to four smells delivered through a pipe to the air above an experimental area. Two of the smells proved far more attractive to the animals than the others. When sniffing both the smell of food and that of five-week-old bottles turtles kept their noses out of the water more than three times as long, and took twice as many breaths as they did when what was on offer was the smell of fresh bottle-plastic or clean water vapour. On the face of it, then, the turtles were responding to the smell of old bottles as if it were the smell of food.
    Though they have not yet tested whether the chemical is the culprit, Dr. Pfaller and his colleagues think it is the most likely candidate. In an unpolluted ocean, pretty well anything which had this smell would be edible—or, at least, harmless. Unfortunately, five-week-old plastic bottles and their like are not.
It was suggested by researchers from University of California, Davis that________.

选项 A、seabirds are prone to feed on plastics which smell of certain chemicals
B、the smell of certain chemicals is the reason why animals are often killed
C、seabirds often chase their food at the bottom of the marine food chains
D、an abundance of bacteria result in the emergence of micro-organisms

答案A

解析 根据题干关键词researchers from University of California, Davis 定位到文章第二段。该段提到研究人员对海鸟喜欢吃塑料垃圾的原因进行了判断。第一句明确指出原因是“塑料垃圾的气味可能会诱使动物走向灭亡”,段落后续内容对其进行了更为详尽的说明,即这些塑料释放了某些化学物质,这些化学物质正是海鸟捕食时关注的那些。所以根据该段的逻辑,A项seabirds are prone to feed on plastics which smell of certain chemicals (海鸟喜欢吃那些有某种化学物质味道的塑料)为正确答案。原文中只指出化学物质是动物被吸引的原因,且根据第一段的内容,动物会死掉,是因为塑料无法在动物体内分解,所以B项the smell of certain chemicals is the reason why animals are often killed(某些化学物质的气味就是动物经常被杀死的原因)属于过度推理,故排除;文章第二段第三句只是说明“细菌”位于“海洋食物链的底端”,与海鸟捕食的位置无关,故C项seabirds often chase their food at the bottom of the marine food chains(海鸟常在海洋食物链底端捕食),属于无中生有,应排除;D项an abundance of bacteria result in the emergence of micro—organisms(大量细菌导致微生物的出现)只是将第二段中出现的两个名词性概念随意拼凑在一起,属于无中生有,故应排除。
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