完形填空
One day a lion met a spider, who was just busy making a web. The lion 1 for a while and said, "How clever you are! How did you learn to do that?" The spider answered proudly, "I learned it from my mother."
The lion watched a longer while. Then he asked the spider, "But why don't you catch your food in the way that I do?"
"I am just a 2 animal," the spider replied. "I cannot run fast or fly. 3 with my web I can catch flying insects, and I don't even have to run after them."
The lion then asked, "Could you make a 4 for me? Then I would not have to run after animals either."
"Sorry," the spider said. "My web can only catch flying insects. But you cannot love 5 them."
The lion was angry with the spider. She did not have to work 6 for food. And she would not help him get his 7. So he hit the web and broke it. But the spider jumped 8 the lion's back and bit him.
"Now you will 9 me," said the spider as she jumped into the grass. "Think carefully 10 you do something bad to other animals. Some of us may be small, but we are very smart."
The lion tried to scratch his back, but he could not reach where the spider bit. It itched(发痒)for several days. He remembered the smart spider for a long time.
。流经导线的电流为I，方向如图中箭头所示。导线段abcd所受到的磁场的作用力的合力