题目

In 1845, a deadly disease struck the farms of Ireland, killing all the Lumper potato plants. In another place or time, the death of single crop species (物种) might not have been so important. But in Ireland, in 1845, people depended almost solely on the patato for food. The death of one species caused a terrible famine(饥荒). Now, some scientists are worried that such a famine could happen again, but on a much wider scale.Over the centuries, farmers have discovered thousands of different species of food crops. Each species has special qualities. Some can be grown in very hot or cold clima读我国某区域等高线图，该区域所属自然带为 A.亚热带常绿硬叶林带     B.亚热带常绿阔叶林带 C.温带落叶阔叶林带       D.热带雨林带