1＼The beaver chews down trees to get food and material with which to build its home.
这只海猩嚼断树枝以获取食物和筑窝的原材料
2。过去人们猎鸭时曾让狮子狗负责取回鸭子，但美国小狗俱乐部并不把狮子狗当个运动型犬，因为它们如今主要被作为宠物来饲养
Poodles were once used as retrievers in duck hunting, but the American Kennel Club does not consider them sporting dogs because they are now primarily kept as pets.
3。如今我们知道，由于物理和化学的研究成果，科学家们已经能够在生物和药理学上取得重大发现。
As a result of what is now known in physics and chemistry, scientists have been able to make important discoveries in biology and medicine.
