Farmland in parts of Japan is no longer safe because of high levels of radiation in the soil, scientists have warned, as the cou

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问题    Farmland in parts of Japan is no longer safe because of high levels of radiation in the soil, scientists have warned, as the country struggles to recover from the Fukushima atomic disaster. A team of international researchers said food production would likely be "severely impaired" by the elevated levels of caesium (放射性铯) found in soil samples across eastern Fukushima in the wake of meltdowns at the tsunami-hit plant. The study suggests farming in neighboring areas may also suffer because of radiation, although levels discovered there were within legal limits.
   "Fukushima area as a whole is highly polluted, " especially to the northwest of the nuclear power plant, the researchers said. The study looked at caesium-137, which has a half-life of 30 years and therefore affects the environment for decades.
   The legal limit for concentrations in soil where rice is grown of the sum of caesium-134 and caesium-137, which are always produced together, is 5, 000 becquerels per kilogram in Japan.
   "The east Fukushima area exceeded this limit and some neighboring areas such as Miyagi, Tochigi and Ibaraki are partially close to the limit under our upper-bound estimate, " the study said. "Estimated and observed pollution in the western parts of Japan were not as serious, even though some areas were likely affected to some extent, " it added.
   "Concentrations in these areas are below 25 becquerels per kilogram, which is far below the threshold for farming. However, we strongly recommend each area to quickly carry out some supplementary soil samplings at city levels to validate our estimates."
   The study said "food production in eastern Fukushima area is likely severely impaired by the caesim-137 loads of more than 2, 500 becquerels per kilogram".
   The study was led by Teppei Yasunari of the Universities Space Research Association in the US state of Maryland. He and his team used daily observations in each Japanese area and computer-simulated particle dispersion models based on weather patterns.
   Japan has been on alert for the impact of radiation since an earthquake and resulting tsunami struck the northeast of the country on March 11, damaging the Fukushima Daiichi nuclear power plant. Its cooling systems were knocked offline and reactors were sent into meltdown, resulting in the leaking of radiation into the air, oceans and food chain.
   Shipments of a number of farm products from the affected regions were stopped and even those that were not subject to official controls have found little favor with Japanese consumers cautious of the potential health effects.
Fukushima atomic disaster’s direct cause is______.

选项 A、the falling of the Fukushima Daiichi nuclear power plant
B、the hurricane
C、the food production is "severely impaired"
D、not mentioned

答案A

解析 本题细节定位于倒数第二段“resulting tsunami struck the northeast of the country on March 11,damaging the Fukushima Daiichi nuclear power plant.Its cooling systems were knocked offline and reactors were sent into meltdown,resulting in the leaking of radiation into the air, oceans and food chain”。由此可知,海啸破坏了福岛第一核电站,冷却系统发生故障,反应堆内的燃料熔毁。因此,其直接原因就是福岛第一核电站遭到损坏,因此选择A。
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