网络交往的对象看不见、摸不着。在网络交往时，我们应该（    ） 

北京市东城区鼓楼苑社区属于文物保护地区，不少住户大院里杂物到处乱放，极易引发火灾。为此，社区采取公开讨论的办法，提出“你周围的消防隐患有哪些”等问题，让居民思考回答，大家感受到消防安全的重要，都主动清理了自家院子。下列选项对这一做法及其意义的概括正确的是（    ）

从所给的四个选项中选出最佳答案，将其序号填入题前括号内。

    A young man 1 himself in Japan with only enough money to buy the ticket for his 2 back home. As he knew that it would take him only two days to 3 home, he decided that he could easily spend the time 4food. So he bought a ticket and 5 the ship. The man 6his ears to the sound of the lunch bell. When dinner 7 came, he didn't go to the dining room, 8 that he was not feeling well. The next morning he still didn't have breakfast and at lunch time he again 9 in his room. But at dinner time he was so hungry that he went to the dining room and 10 everything the waiter put in front of him. “Bring me the bill,” he said. “The bill, sir?” said the waiter in surprise. “There isn't any bill. On our ship meals are included in the money for the ticket.”