1.科学家们不确信恐龙为什么灭绝，但是有些理论假定了地理、气候、海平面的改变是对恐龙的灭绝有影响的
2.园艺科学，就是使用从其它学科里面得来的信息，主要关注于产出最大限地的和更好的质量。
雪可以帮助农民保持浅层地面的热量，从而使种子免遭冰冻。
1. Scientists do not know why dinosaurs became extinct, but some theories postulate that changers in geography, climate, and sea levels were responsible. 点击词典
2. The science of horticulture, in which the primary concerns are maximum yield and superior quality, utilizes information derived from other sciences.
3.Snow aids farmers by keeping heat in the lower ground levels, thereby saving the seeds from freezing. .
