形容人心难以捉摸，民众的行为像烟一样飘忽不定。
To talk about painting is not only difficult but perhaps pointless too.
一本好书是作者与读者之间的对话。
Innovation in forestry means finding ways to do more with less.
粮食安全的未来就在波涛之下，我们有责任明智地开发它。