hints:
最后的人名不用写
How many times have we walked past a piece of litter on the ground, cursing whoever was so thoughtless as to drop it and wondering when someone would come by to clean it up? It wouldn't be hard for us to bend over and pick up the litter, then drop it in the nearest waste bin, after all.
我们曾有多少次走路时看到地上有垃圾时咒骂是谁这么粗心掉下了它，又在想到底什么时候会有人过来清理它。但是毕竟弯腰把它捡起来扔到垃圾桶里也不是什么难事。
