【单选题】A psychrometer has two thermometers that provide dry bulb and wet bulb temperatures. By comparing these two temperature readings with a set of tables you can determine the ______.
【简答题】阅读理解。 About 130 years ago, Thomas Edison of the US invented the light bulb (电灯). Edison's bulb has turned night into day ever since. But today, many want to turn the light off. The European Union (欧盟)...
【简答题】阅读理解。 About 130 years ago,Thomas Edison invented thelight bulb. His bulb turned night into day,but today manypeople want to turn off the light. The European Union( 欧盟) has decided that peo-ple should ...