问题
不定项选择
在做“奥斯特实验”时，下列操作中现象最明显的是 [ ]
A．沿电流方向放置磁针，使磁针在导线的延长线上
B．沿电流方向放置磁针，使磁针在导线的正下方
C．电流沿南北方向放置在磁针的正上方
D．电流沿东西方向放置在磁针的正上方
答案
C
搜题请搜索小程序“爱下问搜题”
在做“奥斯特实验”时，下列操作中现象最明显的是 [ ]
A．沿电流方向放置磁针，使磁针在导线的延长线上
B．沿电流方向放置磁针，使磁针在导线的正下方
C．电流沿南北方向放置在磁针的正上方
D．电流沿东西方向放置在磁针的正上方
C
| 完形填空。 | ||||
| Mary was four years old. Her neighbour, Donald, owned a 1 company. One day Donald gave Mary a new toy. Mary played with it. She said, "This is fun!" A few weeks 2 Donald gave her another toy. She played with it and said, "I don't like this toy. It doesn't work." She was a (an) 3 little girl. Donald liked her honesty, and they became 4 For years Donald gave Mary new toys, and she gave him very good ideas 5 the toys. 6 Mary was thirteen years old, Donald showed her a new ball. The ball 7 a balloon inside it. Mary wanted to fill the balloon with water. She wanted to 8 the ball different colours. She wanted to put rice in it to make it noisy. The company made these 9 and sold thousands of the balls. That Christmas, Donald gave Mary a 10 gift. He made her a vice (副的) president of the toy company. Her job was to see 11 the new toys were fun. She made $200,000 a year. She 12 for three hours a day at her job, and then she had to do her homework. Mary was 13 , but she also spent time with her family. 14 parents taught her that working hard and doing her best is very important. Today Mary works at a college. She 15 students make decisions about their careers (生涯). Today the little president with bright ideas helps students think about their future. | ||||
|