河南成教 / 大学英语
正确率：100%
48[单选题]
_ _ _ _ _ _ _ _ the city's environment(环境) has become of great importance.
A.The improving
B.Improving of
C.Improving
D.Being improved
_ _ _ _ _ _ _ _ the city's environment(环境) has become of great importance.
参考答案：
佳题速递：