Various efforts over the centuries to predict earthquakes to reduce the damage. A. are b

问题补充：

Various efforts over the centuries to predict earthquakes to reduce the damage.

A. are being made

B. have been made

C. were made

D. were being made

答案：

A. are being made

(答案→)B. have been made

C. were made

D. were being made

解析：句意：几个世纪以来，已经做了各种努力来预测地震，减少损失。make efforts 做出努力，变被动形式。故选B。

考点: 考查动词时态和语态的用法。