分析频闪照片可知：

银镜反应是检验醛基的重要反应，教材对该实验的操作条件只是粗略的描述．某同学进行如下研究：

①金文②甲骨文③陶文④铭文

    One day, in an English class, the students are doing their lessons. Their teacher, a young woman, is very happy. She sings with them and then she goes to the blackboard and writes “SMILES” on it.
    “This is the longest word in English,” she says to the class.
    A girl stands up and says, “It has only six letters. How can it be the longest word in English?”
    The teacher smiles and says, “Oh, look! There is a mile (英里) between the first letter and the last one.”