We are confident that the environment by our further efforts to reduce pollution.A. impro

问题补充：

We are confident that the environment by our further efforts to reduce pollution.

A. improves

B. will be improved

C. has improved

D. was improved

答案：

A. improves

(答案→)B. will be improved

C. has improved

D. was improved

解析：句意：我们确信经过我们减少污染的进一步努力，环境会被改善的。根据are confident我们现在确信， by our further efforts通过进步的努力，那环境的改善应是在将来，又因 主语environment 与谓语improve之间是被动关系，故用一般将来时的被动式。故选B。