问题
选择题
电灯的亮度取决于（ ）
A．加在电灯两端的电压
B．通过电灯的电流
C．电灯的额定功率
D．电灯的实际功率
答案
答案：D
电灯的亮度取决于电灯的实际功率，选D
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电灯的亮度取决于（ ）
A．加在电灯两端的电压
B．通过电灯的电流
C．电灯的额定功率
D．电灯的实际功率
答案：D
电灯的亮度取决于电灯的实际功率，选D
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| In the busy working time most people are busy working or studying from Monday to Friday, but in the evenings and weekends they are free and 1 themselves. Some watch television or go to the movies, others 2 sports. This is decided by their own 3 . There are many different ways to spend our 4 time. Almost everyone has some kind of 5 : it may be something from collecting stamps to 6 model planes. Some hobbies are very 7 , but others don't cost anything at all. Some collections are worth 8 of money, others are valuable only to their owners. I know a man who has a coin collection worth several 9 dollars. A short time ago he bought a rare fifty-cent piece which 10 him $250! He was very happy about this collection and thought the price was all right. On the other hand, my youngest brother collects match boxes. He has almost 600 of them, but I wonder 11 they are worth any money. However, 12 my brother they are quite valuable. 13 makes him happier than to find a new match box for his collection. That's what a hobby means, I think. It is something we 14 to do in our free time just for the 15 of it. The value in dollars is not important, but the pleasure it gives us is. | ||||
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