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单选题

A．They can be used to deliver messages in times of emergency.
B．They deliver pollutants from the ocean to their nesting sites.
C．They carry plant seeds and spread them to faraway places.
D．They are on the verge of extinction because of pollution.

参考答案B

解析:Birds are famous for carrymg things around．Some，like homing pigeons，can be trained to deliver messages and packages．Other birds unknowingly carry seeds that cling to them for the ride．(9)Canadian scientists have found a worrisome．new example of the power that birds have to spread stuff around．Way up north in the Canadian ArctiC．seabirds are picking up dangerous chemicals in the ocean and delivering them to ponds near where the birds five．
Some l0．000 pairs of the birds，called flllitlars，a kind of ArctiC seabird．make their nests on Devon Island．north of the Arctic Circle．(10)The fllfinars travel some 400 kilometers over the sea to find food．
When they return home，their droppings end up all around their nesting sites，including in nearby ponds．
(11)Previously．scientists noticed ponutants arriving in the Arctic with the wind．Salmon also carry dangerous chemicals as the fish migrate between rivers and the sea．The bodies of fish and other meat—eaters Can build up high levels of the chemicals．
To test the polluting power of fulmars，researchers coUected samples of deposit from 11 ponds on Devon Island．In ponds closest to the colony，the results showed there were far more pollutants than in ponds less affected by the birds．The poHutantS in the ponds appear to come from fish that fulIIlars eat when they’re out on the ocean．(12)People who five，hunt，or fish near bird colonies need to be carefitl，the researchers say．The birds don’t mean to cause harm，but the chemicals they calTy Can cause major problems．
预览四道题各选项，由defiver，nesting sites，carry和migrate等词可以初步判断，短文与鸟类的迁移过程中可携带某种东西有关，再结合Arctic Circle，poisonous，threats和harm等词可以进一步推测，短文与海鸟给北极地区带来有毒物质有关。
What have Canadian scientists found about some seabirds?
B。短文开头提到，鸟类以传送物品而闻名，而加拿大科学家发现了一个令人担忧的说明鸟类具有散播物品能力的新例子。在加拿大极地的北部，海鸟们捡起海水中的危险化学品，带回到它们的栖息地附近的池塘中，故答案为B。

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单选题

A．They migrate to the Arctic Circle during the summer.
B．They originate from Devon Island in the Arctic area.
C．They travel as far as 400 kilometers in search of food.
D．They have the ability to survive in extreme weathers.

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单选题

A．They were carried by the wind.
B．They had become more poisonous.
C．They were less than on the continent.
D．They poisoned some of the fulmars.

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单选题

A．The threats humans pose to Arctic seabirds,
B．The diminishing colonies for Arctic seabirds.
C．The harm Arctic seabirds may cause to humans.
D．The effects of the changing climate on Arctic seabirds.

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