考古发现是了解史前社会的主要证据．下面一组邮票反映的是河姆渡遗址发掘出的文物，它见证了我国河姆渡原始居民的生产生活状况．据此可以得出的结论有（　　）

①他们种植的农作物是水稻     ②他们主要使用青铜农具

③他们居住的是干栏式房屋     ④他们已学会了制作舟船．

日前，公安部公布了《治安管理处罚法（修订公开征求意见稿）》，将行政拘留执行年龄从16周岁降低至14周岁。近年来，青少年违法低龄化日益突出，涉黄、涉毒、打架斗殴等现象多发，究其原因，青春期具有很强的叛逆性、冲动性，容易不计后果实施危害行为。这告诉我们（    ）

根据短文理解，选择正确答案。

    An old man was fishing on the bank of a river. A child came to see him fishing. The old man was really good at fishing and it didn't take long for him to catch a full basket of fish. The old man saw that the child was very cute, and he wanted to give her a whole basket of fish. But the child shook her head.

    The old man was surprised and asked, "Why don't you want the fish?"

    The child answered, "I want the fishing rod(竿)in your hands."

    The old man asked, "Why do you want the rod?"

    "It doesn't take long to eat all the fish in a basket. But if I have the fishing rod, I can go fishing by myself and I won't be afraid of not having any more fish to eat."

    I think you will certainly say that the child is very smart. Wrong! If she doesn't know how to fish, she can not have fish to eat, even though she has the fishing rod. It's useless to only have a fishing rod. Fishing skills are the most important, not the fishing rod.

    Too many people think that if they have a "fishing rod" in their life, they will no longer fear(害怕)the wind and rain. They are just like the child, who thought that if she had a fishing rod, she would have fish to eat.