题目

In the United States, friends can be close, constant, intense, generous, and real, yet fade away in a short time if circumstances（环境）change．Neither side feels hurt by this．Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while then no more．If the same two people meet again by chance, even years later, they pick up the friendship where it left out and are delighted. In the States, you can feel free to visit people’s homes, share their holidays, enjoy their children and their lies without fear that you taking on a lasting obligation（负有一个长方体的房间，长10米，高3米，宽6米，需要在四周和天花板上粉刷涂料，整个房间里门窗的面积是36平方米，每平方米用涂料0.5千克，需要用涂料多少千克？考虑到使用中的损耗，需要多买110，实际要买多少千克涂料？