1 The beaver chews down trees to get foods and materials with which to build its home
海狸啃断大树获取成家所需的食物和材料
2 Poodles were once used as retrievers in duck hunting ,but the American Kennel Club does not consider them as sporting dogs, because now they are primarily kept as pets
狮子狗曾被用作猎鸭过程中取回猎物之用，但美国狗友俱乐部把它们列为运动型狗，应为今天它们主要被当作宠物饲养。
3 As a result of what is known in physics and chemistry,scientists have been able to make important discoveries in biology and medicine
作为物理学和化学研究的衍生，科学家们已经能够在生物医药方面有重大发现。
