【试题设计】材料一大白菜是原产于我国的一种常见蔬菜,喜温和冷凉的气候条件,生长适温在10~22℃,高于25℃时生长不良,生长期要求有充足的光照条件和水分供应。材料二甘肃省榆中县农业过去以种植粮食作物为主,经济比较落后。21世纪以来,该地开始大规模种植以大白菜为代表的冷凉蔬菜。经过长期的自然选择和人为精心选育,榆中县蔬菜种植品种现已达360多 【Problem】 design a cabbage is a common vegetable originating in our country, like the warm and cool climatic conditions, the growth of suitable temperature at 10 ~ 22 ℃, higher than 25 ℃ poor growth, growth period requires adequate Light conditions and moisture supply. Material II Yuzhong County, Gansu Province, agriculture in the past mainly to grow food crops, the economy is relatively backward. Since the 21st century, large-scale cultivation of cool vegetables such as Chinese cabbage has begun. After long-term natural selection and man-made careful breeding, Yuzhong vegetable planting varieties have now reached more than 360