Scientists have always believed that snails are not able to find their way home. But Briton Ruth Brooks, a retired teacher, has found that it is not true.

    Brooks began an experiment on snails after she got mad with the snails in her garden.

    The snails had eaten her vegetables. She didn't want to kill them, so she took them to another place. But she found they always seemed to come back.

    Brooks did an experiment. She marked the snails in her garden with nail polish(指甲油).

    She placed the snails in the area around her home and made notes of their movements.

    She found that snails have a strong homing instinct (本能); the longest returning snail traveled back 90 meters. Brooks has been named Britain's best amateur (业余的) scientist after her work won the BBC Radio 4 project, So You Want To Be A Scientist.

    She said, "I've always wanted to know whether the snails that eat my plants just come back when I move them, and if they do, what is their homing distance?

    "I would say on the evidence (证据) that it would be safe to take your snails away beyond 100m or even further. If you put them somewhere nice with some food, you can be almost certain that they won't come back."

按要求完成下题。

                                                                                                梁 园 
                                                                                             唐   岑参
                                                                             梁园日暮乱飞鸦，极目萧条三两家。
                                                                             庭树不知人去尽，春来还发旧时花。
     【注】梁园：在今河南商丘县东，西汉梁孝王刘武所建，曾经繁盛一时。