去年，佛罗伦萨制定了一项规则，游客如果被发现在街上吃东西，将面临最高500欧元的罚款。

Last year, Florence made a rule saying that tourists would face fines of up to 500 euros if caught eating in the street.

youdao

那和年幼时在公园里玩的捉迷藏没什么区别，只是如果被发现就要挨枪子儿。

It's just like those youthful days of hide-and-seek in the park, the critical difference being that you get shot if someone finds you.

youdao

如果被发现在野外雨林地层上落叶里，它们能够将自己假装成枯叶来欺瞒过肉食动物。

Found in the wild living amongst fallen leaf litter on rainforest floors, they are able to cheat predators by disguising themselves as dead leaves.

youdao

And so, he has put this chemistry to use in this robotic arm and they call it Fido, because often dogs are the creatures that have to go out and detect these things, and it's not a great job if you're a dog to be sent out to see whether there was an explosive and discover yes, there was, a little bit too late.

因为通常都是派狗去检查这些东西,这个不是个好工作，如果你是一只狗,被派去检查是否有爆炸物，然后你发现有,那就来不及了,所以用机器手检查化学物质。

麻省理工公开课 - 化学原理课程节选