题目

A: On today's Words and Their Stories we talk about a common word, a small word, but a word that is completely necessary for human life. In fact, without this simple, everyday material, all humans would die. B: Scientists know it as sodium chloride. We know it as salt. You may think, salt is just a simple cooking element we shake on our food for a little extra taste. But salt is much more than that. A: Without salt our muscles would not move. Our nervous systems would not operate. Our hearts would not beat. Salt means life. But do not think rubbing salt in a wound will help. Doing that wo2．雨后晴朗的夜晚，地上有积水，当你背着月光向前走时，地上有积水的地方较暗（选填“较亮”或“较暗”）．游泳池注水后，看上去好像变浅了，这是由于光的折射形成的．