Measures must be taken to prevent pollution happily.
A. from we live
B. for us to live
C. us living
D. from our living
网友回答
A. from we live
(答案→)B. for us to live
C. us living
D. from our living
解析：句意：对于我们来说，为了幸福地生活着，我们必须采取一些措施阻止污染。for us对于我们来说，to live不定式表示目的，故选B