题目内容：

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

Crows(乌鸦) are remarkably intelligent birds. Now these feathered geniuses are given a job: Six crows have been trained to pick up rubbish in the Puy du Fou historical theme park in western France. Whenever the six crows put cigarette ends or other small 1. (piece) of trash in a special container, it offers a treat to reward the crows 2. their efforts.

The idea came from one of the park’s employees, Christophe. In 2012, the theme park held a show during which the crows picked up roses and brought them to a “princess”. It was the show 3. inspired him. Since then, six crows 4.(raise) and trained to do the same with rubbish. The training system is similar to the one for testing crows’ intelligence, 5. a food dispenser(分发器) gives away a food reward when a crow 6. (correct) performs a task. Christophe also introduced other species of birds to go through the training. 7. (compare) with other birds, crows are much cleverer.

The purpose of 8. (train) the crows is to educate the people to reflect on themselves. Since the birds are able to protect the environment, we need to care about it too. “It is 9. funny way to remind people not 10.(throw) the rubbish everywhere,” said Christophe.