【题目】A public health campaign _____ the number of heart disease deaths by 80 percent over the past three decades．
A．had reduced B．had been reduced
C．has reduced D．has been reduced
在线课程【答案】C
【解析】Campaign,n．运动。Over the past+时间，在过去的…… 该时间状语表示现在完成时，即已经减少（“has reduced”）