题目

      ①I will think of it. It is easy to say this, but do you know what great things have come from thinking? Though we can not see, or hear, or feel our thoughts, they have great power (力量) !       ②Isaac Newton was seated in his garden on a summer evening when he saw an apple fall from a tree. He began to think, and tried to find out why the apple fell. Then he discovered how the earth, sun, moon, and stars are kept in their places.     ③James Ferguson once saw the inside of his father's watch, and he wondered, Why should I not make a watch? This set him thinki19世纪，英国为改变与中国贸易中的不利地位，向中国输入鸦片,给中国带来了严重的危害。下列属于鸦片输入带来的危害的是①使中国的白银大量外流  ②严重影响了清政府的财政收入，加重了农民的负担③清朝政治更加腐败  ④军队战斗力进一步削弱A.①②③B.①②④C.①③④D.①②③④