把在野外采集的浮萍放在盛水的大烧杯内,让学生将小烧杯里的水向大烧杯倾倒,可见漂浮在大烧杯水面上的叶状体受到水流的冲击却没有被打得翻转不定,即使个别零散的叶状体被打翻了,也很快就恢复了原来的状态。当把这些浮萍的根剪掉之后,再重复上述实验,可见这些浮萍的叶状体不但被打得翻转不定,而且被打翻后不再恢复原来的状态了。这样就使学生不但能观 Put the duckweed collected in the wild in a large beaker of water to allow the students to pour the water from the small beaker onto the large beaker. The frond floating on the beaker’s surface is not affected by the water flow but flipped Indefinite, even if the individual fragmented frond was knocked over, but also quickly restored to its original state. When these duckweed roots were cut off, the above experiment was repeated, showing that the duckweed fronds were not only flipped, but were no longer restored to their original state after being overturned. This will enable students to not only view