Parls of the palace of Versailles may have to be closed to the public in order to preserve them,and some European caves,famous for their thirty-thousand-year-old paintings,have already been closed because the paintings were damaged by human respiration.

• 凡尔赛宫中有些地方可能要停止对公众开放，以期能保存下来。欧洲有一些以有三万年历史的古画而著称的洞窟已经关闭了，因为那些画已受到人类呼出的空气的损坏。