问题
多选题
| 关于磁场，下列说法正确的是（ ） A．所有的磁现象都是由运动电荷（或电流）产生 B．磁场产生电场，电场也一定能产生磁场 C．磁场的方向可以由小磁针N极受力的方向来确定 D．安培提出用右手螺旋定则判断电场和磁场的方向关系 |
答案
ACD
搜题请搜索小程序“爱下问搜题”
| 关于磁场，下列说法正确的是（ ） A．所有的磁现象都是由运动电荷（或电流）产生 B．磁场产生电场，电场也一定能产生磁场 C．磁场的方向可以由小磁针N极受力的方向来确定 D．安培提出用右手螺旋定则判断电场和磁场的方向关系 |
ACD
| 完形填空 | ||||
| In 1883, a creative engineer, John Roebling, was inspired to build a splendid bridge connecting New York with Long Island. However, experts throughout the world thought that this was__1__. Even so, Roebling could not__2__the idea in his mind. After much discussion, he__3__convince his son Washington, an up-and-coming engineer, that the bridge in fact could be built. They hired their__4__and began to build their dream bridge. Only a few months__5__the project was underway, a tragic on－site accident killed John Roebling and__6__injured his son, leaving him brain-damaged and unable to move or__7__. Surely now the project would have to be__8__. Though Washington Roebling lay in his hospital bed, he was not__9__ and his mind remained as__10__as it was before the accident.Suddenly an idea__11__him. All he could move was one finger, so he__12__the arm of his wife with that finger, __13__to her that he wanted her to call the engineers again.Then he used the same method of tapping her arm to tell the engineers what to do. For 13 years Washington tapped out his__14__with one finger until the bridge was__15__ completed. Perhaps this is one of the best examples of never-say-die attitude that__16__a terrible physical disability and achieves an impossible__17__. Often when we face difficulties in our daily lives, our problems seem very small__18__what many others have to face. The Brooklyn Bridge shows us that even the most__19__dream can be realized with__20__no matter what the chances are. | ||||
|