We are confident that the environmenr by our further efforts to reduce pollution
A. had been improved
B. will be imroved
C. is improved
D. was improved
网友回答
A. had been improved
B. will be imroved
C. is improved
D. was improved
解析：句意：我们相信我们进一步减少污染的努力将会改善环境状况。根据题干中主句是将来时，还有空后的further判断此处应用将来时。
【考点定位】考查时态和语态。