以前,没有电灯,这给人们的生活带来许多不便。没有电灯,人们只好点煤油灯。但是,煤油灯的光线太暗了,看不清人和物。再则,煤油灯燃烧放出的烟雾太浓,会把人们的鼻孔和面孔熏黑,影响人们的健康。现在有了电灯,方便多了。但是,电灯还有很多弊端和不足。比如,它的寿命太短,电流强了,容易烧掉,而且灯泡的光线强度是规 In the past, there were no lights, which brought many inconveniences to people’s lives. Without lights, people had to point kerosene lamps. However, the light of kerosene lamps is too dark to see people and things. In addition, kerosene lamps emit too much smoke burning, will make people’s nostrils and faces blackened, affecting people’s health. Now with the lights, much more convenient. However, there are many shortcomings and deficiencies of electric lights. For example, it’s life is too short, the current is strong, easy to burn, and light bulb light intensity