题目内容
（请给出正确答案）
[主观题]
Many disasters allow no time for people to gather even the most basic necessities, wh
ich is()planning ahead is essential.
A. why
B. because
C. since
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The room is a vault (地下库) designed to hold around 2 million seeds, representing all known varieties of the world's crops. It is being built to safeguard the world's food supply against nuclear war, climate change, terrorism, rising sea levels, earthquakes and the collapse of electricity supplies. "If the worst came to the worst, this would allow the world to reconstruct agriculture on this planet," says Cary Fowler, director of the Global Crop Diversity Trust, an independent international organization promoting the project.
The Norwegian (挪威的) government is planning to create the seed bank next year at the request of crop scientists. The $3 million vault will be built deep inside a sandstone mountain on the Norwegian Arctic island of Spitsbergen. The vault will have metre-thick walls of reinforced concrete and will be protected behind two airlocks and high-security doors.
The vault's seed collection will represent the products of some 10, 000 years of plant breeding by the world's farmers. Though most are no longer widely planted, the varieties contain vital genetic properties still regularly used in plant breeding.
To survive, the seeds need freezing temperatures. Operators plan to replace the air inside the vault each winter, when temperatures in Spitsbergen are around -18℃. But even if some disaster meant that the vault was abandoned, the permanently frozen soil would keep the seeds alive. And even accelerated global warming would take many decades to penetrate the mountain vault.
"This will be the world's most secure gene bank," says Fowler. "But. its seeds will only be used when all other samples have gone for some reason."
The project comes at a time when there is growing concern about the safety of existing seed banks around the world. Many have been criticized for their poor security, ageing refrigeration (冷藏) systems and vulnerable electricity supplies.
The scheme won UN approval at a meeting of the Food and Agriculture Organization in Rome in October 2005. A feasibility study said the facility "would essentially be built to last forever".
The Norwegian vault is important in that ______.
A．the seeds in it represent the rarest varieties of world's crops
B．the seeds in it could revive agriculture if the worst thing should happen
C．it is built deep in a mountain on a freezing-cold Arctic island.
D．it is strong enough against all disasters caused by man and nature
