Dogs like living with people. They are very friendly. They can do many things for people.   Some dogs help people to look after sheep, other dogs help them to find the lost children.① And some of the dogs can help the blind.(盲人)

   There is a kind of dog whose name is Seeing Eye Dog②. Now we can see this kind of dog all over the world. They are working for the blind. The Seeing Eye Dog is strong and easy to train(训练). He helps the blind to walk from place to place. Before a dog becomes a Seeing Eye Dog, he must be in a training school for about three months. First the dog has to learn to sit or stay when he hears the trainer's call. In his next lesson the dog learns to take his trainer across busy streets ③. The dog has many things to learn. 在……的末尾④the training, he must take tests. When he passes the tests, the Seeing Eye Dog will do things by himself.   Now he can help the blind people. The new master(主人) may be a man , a woman or even a child. It takes the dog and his blind master about a month learning to work and live together.⑤

结合材料，回答下列问题。

材料一：16岁的男孩小华虽然从小爱玩好动，但学习成绩还算不错。这个年纪的孩子，爱打游戏机的挺多，小华也不例外。一次，在游戏机房里，小华认识了一群“哥们”。他们掏出一种白色粉末，围坐在那里吸，一副“飘飘欲仙”的样子，一下子就引起了小华的好奇。当“哥们”怂恿他尝一口时，小华毫不犹豫地伸出了手。有了第一次，就有了第二次、第三次。后来，为了弄钱吸毒，小华开始学会说谎，学也没心思上了，有时骗一些低年级同学的钱。有一天，他竟然持刀抢劫了一名女青年的钱包……最终，小华受到了应有的惩罚。材料二：小军原来是班里的先进青少年，他的成绩在班上名列前茅，他在同学们的心目中既阳光帅气还乐于助人，他们都称赞小军可以考上北大清华，没想到的是，小军在周末时结识了一位叫尜尜的网友，他们约好见面，谁知道他们见面的3分钟后，小军和那名结识的网友消失的无影无踪，家长知道孩子的情况后，十分痛心，找了三个月，才发现小军已经被那名网友拐去了网易网吧，当发现时小军嘴里咬着烟头，头往上仰，眼睛已经闭上了，经医院检查，小军因吸取毒品，过度劳累，早已死去了。

①实践推动人们进行新的探索和研究

②实践是认识产生的唯一途径

③认识只有服务于实践才彰显其意义

④认识有多深刻决定了实践能走多远