题目

He made up his mind to devote his life _______ pollution _______ happily. A. to prevent; to live                 B. to prevent; from living C. to preventing; to live               D. to preventing; living 答案：C一个数与它倒数相除，商（　　）A．一定大于1B．一定小于1C．一定等于1D．不确定