WE usually think of plants as the furniture of the natural world. They don’t move; they don’t make sounds; they don’t seem to respond (反应) to anything – at least not very quickly. Grass doesn’t cry when you cut it; flowers don’t shout at you when they’re picked. But now we know that our human view of the world is not quite correct. Plants talk to each other all the time. And the language is chemical (化学的).