59. bioclock: 海滩上有种东东, 好长的单词, 象是一种海藻, 当潮水来前那一刻会马上缩进海滩里, 退潮后又会出现. 很准时并且都是在白天. 这种现象引起了科学家的兴趣, 就来研究了(吃饱了撑着?) 还带了一些回去. 发现在实验室持续灯光下, 其它条件也不变的情况下, 这些alga still burrow in and out in some days. then they conclude that there must be something inside themseleve that enalbes these functions. researchers hypothesis it is a bioclock. Second para. these alga s behaviors can also be altered by some environmental means. they compare this to a human watch: people cannot make watch run faster or slower but certainly can change watch time by reseting watch hands...