We are confident that the environment by our further efforts to reduce pollution. (2013·辽宁，30)
A. had been improved
B. will be improved
C. is improved
D. was improved
网友回答
A. had been improved
(答案→)B. will be improved
C. is improved
D. was improved
解析：
考查时态。根据we are confident和by our further efforts可知，环境得到改善应该是将来的事情，故用一般将来时的被动语态。