一、介词by的用法1、 意为“在旁”，“靠近”。Some are singing and dancing under a big tree。Some are drawing by the lake。有的在大树下唱歌跳舞。有的在湖边画画儿。2、意为“不迟于”，“到时为止”。Your son will be all right by supper time。你的儿子在晚饭前会好的。How many English songs had you learned by the end of last term？到上个学期末你们已经学了多少首英语歌曲？3、表示方法、手段，可译作“靠”、“用”、“凭借”、“通过”、“乘坐”等。The monkey was hanging from the tree by his tail and laughing。猴子用尾巴吊在树上哈哈大笑。The boys father was so thankful that he taught Edison how to send messages by railway
