题目

关于如图11-2所示装置的叙述，正确的是（    ）                                                   图11-2A.铜是阳极，铜片上有气泡产生B.铜片质量逐渐减少C.电流从锌片经导线流向铜片D.氢离子在铜片表面被还原 答案：解析:由题给图示可知Zn为原电池负极，失去电子被氧化，电子经导线流向正极铜电极，溶液中的氢离子在正极得到电子而被还原为H2。原电池只分正极、负极，不用阴极、阳极表示，电流与电子流的方向相反。答案:D Many people may enjoy travelling by air, but few like airline food. Airlines have always tried to improve the food quality and the taste in order to attract more travelers. 1. According to some recent scientific researches, a part of the reason is that at high altitude(海拔), we can’t actually taste things well as we do on the ground.Scientists have found that even before a plane takes off, 2. As the plane climbs, the air pressure changes and our noses become more and more senseless. When the plane goes 35,000 feet high, 3. They help explain why the tomato juice on airplanes tastes far less sour in the air than it does down on the ground.4. Otherwise, the food would be tasteless. Astronauts also have to do with this problem on their journeys for similar reasons.5.The studies are going on! We are looking forward to any improvements.A. the nose no longer knows just like being bitten(咬) by a snake.B. How to solve this problem?C. the air inside the plane dries out the nose.D. Getting something tasty in the air is like a dream to the travelers.E. It also helps to explain why airlines like to have salty and spicy(辛辣的) food better.