科学家不知道恐龙为何灭绝，但是一些理论假设地形，气候，海平面的变化将对此负责。
Scientists do not know why dinosaurs became extinct,but some theories postulate that changers in geography,climate,and sea levels were responsible.
园艺学利用其他学科的信息最大化收益和提高质量。
The science of horticulture, in which the primary concerns are maximum yield and superior quality ,utilizes information deriverd from other sciences.
雪帮助农民保持了地表热量，因此保护种子远离寒冷。
Snow aids farmers by keeping heat in the low ground levels,thereby saving the seeds from freezing.
