A
Agricultural experts say crop diversity is important to feed the increasing population of our planet. They say having a large variety of plants also helps to protect against possible crop diseases and future crises. Hundreds of thousands of different plants now exist. But many experts say the number has decreased sharply during the past century.
One of the world’s largest seed conservation projects has predicted further losses. The Millennium Seed Bank is warning that up to one hundred thousand plant species could permanently disappear. The rich collection of genes that decide their qualities would disappear with them.
Many experts blame climate change and loss of habitat, normal growth area, for damaging plant life. They say human activities and poorly planned, overly heavy use of land also are responsible.
The United Nations Food and Agriculture Organization says modern business farming is responsible for loss of farmers’ traditional crop varieties. The “Green Revolution” of the twentieth century changed agriculture. Some experts say the use of modern commercial farming methods saved millions of people from starvation. Farmers planted, watered, and fertilized their crops with the help of machines. They treated their fields with chemicals to control insects and diseases. Harvests grew larger and higher quality.
But another result was that some traditional crops were lost. About one hundred twenty crops are grown to feed humans. The FAO says nine of those crops provide seventy five percent of human food. Rice, wheat and maize are said to supply more than half of human food.
Not all experts agree that. A recent study showed a different situation, at least in the United States. The study examined records of plant varieties in America during the past century. They found that the total number of vegetable and apple crop varieties in the United States did not fall over the past century.
【文章大意】这是一篇说明文。农作物的多样性对养活不断增长的人口很重要, 但是世界上有很多正在消失的植物品种。
1. What does the underlined word “that” in the last paragraph refer to?
A. The loss of farmers’ traditional crop varieties.
B. The number decreasing in food crops.
C. The number increasing in food crops.
D. The disappearance plants species permanently.
【解析】选B。代词指代题。画线词“that”指代的是上文的内容, 第一段最后一句But many experts say the number has decreased sharply during the past century. 但是许多专家说在过去的一个世纪里, 这个数字急剧下降。可知B项正确。
2. Which of the following statements is true?
A. All the experts hold the view that the number plants has decreased sharply.
B. The number of varieties has increased a lot in America.
C. Chemicals has helped harvests grow larger and higher quality in a sense.
D. Terrible weather leads to a decrease in food crops.
【解析】选C。细节理解题。A项中 All the experts表述有误, 并不是所有的专家。B项中increased a lot表述有误, the total number of vegetable and apple crop varieties in the United States did not fall over the past century。D项天气原因只是其中一个方面。故选C。
3. What is the Seed Bank’s attitude towards the disappearance plants species ?
A. Casual. B. Doubtful.
C. Optimistic. D. Concerned.
【解析】选D。推理判断题。 从第二段中The Millennium Seed Bank is warning that up to one hundred thousand plant species could permanently disappear. 千年种子库警告说, 多达十万种植物物种可能永久消失, 可知, warn表达了极大关注, 故选D。
4. Which of the following can be the best title for the text?
A. Showing concern about the disappearance of plant life.
B. Agriculture is playing an important role.
C. The changing of modern agriculture.
D. The Earth in danger.
【解析】选A。主旨大意题。在第一段最后一句“But many experts say the number has decreased sharply during the past century. ”中, “But” 是关键词, 表示转折, 植物品种的数量在下降, 可知选A。
