We were very much surprised at the way ___ she treated the old woman.

A．on which

B．by which

C．to which

D．in which

　　读下面的歌词，请判断，歌词内容与当今全人类所关心的一个什么重大问题有关？请用一个四字短语作答。

       当天空失去了蓝色／小鸟也不会飞翔／当江河不再清澈／鱼儿也离开了家乡。

       当空气不再清新／花朵失去了芳香／当乌云遮住了太阳／世间也将黑暗无光。

答：口口口口