题型:阅读理解 题类:常考题 难易度:普通
四川省眉山市2019-2020学年高一下学期英语期末考试试卷
Travelers to the Arctic islands of Svalbard would find a rough, ice-hardened land, sheltering polar bears in its frozen landscapes. This group of Norwegian islands is the land of the "midnight sun" with almost 24 hours of sunlight during the winter months. It is also home to one of the most important storage facilities in world farming — the Svalbard Global Seed Vault.
The seed vault was opened in 2008 in an effort to safeguard the world's food supply for future generations. Svalbard is the perfect frozen environment to house seed samples, set inside an Arctic mountain at 130 meters above sea level, so it is unlikely to be flooded. Low humidity, geological stability, and the surrounding permafrost can keep seed-keeping places cool, dry, and usable for centuries.
Seed gene banks from around the world have sent food crops seeds for safety in case a natural disaster or environmental damage destroys existing supplies. Worldwide there are more than 1.700 seed gene banks that store seeds locally and many choose to send back-up samples to facilities like the Svalbard's vault.
There is space in the global vault for 4.5 million different crop varieties with each variety storing on average 500 seeds, meaning it can house 2.5 billon seeds. There are around one million seed samples from 80 institutes in the vault at present so there is a lot of spare capacity for the vegetables, grains, peas and beans that are banked annually. On the top of that, there are rare flowers from the Myanmar rain forests.
The largest numbers of samples in the vault are varieties of rice and wheat. The seed vault has been listed as one of the most influential projects of the past 50 years for its efforts. Seeds themselves are not kept for farmers or gardeners to grow produce. Their true value is as a genetic resource in plant upbringing to create new crop varieties.
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