题目内容：

    If you’ve been paying attention, you know that crows (乌鸦) are remarkably intelligent birds. 1.: six crows have been trained to pick up rubbish in the Puy du Fou historical theme park in western France. 2., it dispenses (分发) a treat to reward the crows for their efforts.

The idea came from one of the park’s falconers (放鹰员), Christophe Gaborit. As part of the falconry show, crows had already been trained to pick up roses and bring them to a princess. So in the 2000s, Gaborit raised and trained two crows to do the same with rubbish. 3., in which a dispenser gives a food reward when a crow correctly performs a task.

Earlier this year, we saw research in which a type of “vending machine” was used to teach crows how to tear paper into a specific shape. And 10 years ago, “hacker” Josh Klein built a similar vending machine to reward crows for getting back lost money. 4..

The crows were used for the first time over the weekend, and they'll be working four days a week under close watch —not for the birds, but to make sure the humans don’t deliberately drop rubbish to watch the birds clean it up.

That's because the aim of the crow garbage collectors isn't merely to collect garbage—it's also to get park-goers to think before they litter. 5..

A.So we know the concept works

B.But bird lovers have different views

C.Now these feathered talents have been given a job

D.The crows are trained to identify small pieces of rubbish

E.Whenever they put a small piece of rubbish in a special container

F.It’s a funny way to show the people that you cannot throw the papers everywhere

G.The training system is similar to experimental setups for testing crows’ intelligence