同学们，你知道气压式热水瓶为什么一压就出水吗？我们来做个实验，你就知道了。材料：带盖大口透明塑料瓶（玻璃瓶也可），一根较长的塑料管或玻璃管，橡皮泥或胶水，一个软质小口塑料瓶。实验：在大瓶盖挖出一大一小两个孔（小孔能插进玻璃管，大孔能插进小塑料瓶口），把玻 Students, you know why the pressure thermos a pressure on the water it? We have to do an experiment, you know it. Material: Large transparent plastic bottle with lid (glass bottle can also be), a long plastic pipe or glass tube, plasticine or glue, a soft small plastic mouth. Experiment: In a large cap dug a large one small two holes (holes can be inserted into the glass tube, a large hole can be inserted into a small plastic bottle), the glass