在顺利传递审美信息的过程中，导游应采用恰当的方式使游客从一般的以生理快感为主要特征的“______”的审美体验，升华到以精神愉悦为主要特征的“______”的审美体验，尽可能最终达到以道德和理性启示为主要特征的“悦志悦神”的审美体验。

The human beings have polluted the environment seriously. It is time the United Nations must take some measures.

A. take
B. taking
C. to take

D. took