We all know laws to discourage the use of plastic bags in many parts of the world.A. pass

问题补充：

We all know laws to discourage the use of plastic bags in many parts of the world.

A. passed

B. have passed

C. had been passed

D. have been passed

答案：

A. passed

B. have passed

C. had been passed

(答案→)D. have been passed

解析：考查动词的时态。句意为“我们都知道不提倡使用塑料袋规定已经在世界许多地方通过”。主语为laws，用被动是一定的。根据语境可知用had been passed明显错误，只有D可以理解。此处用were passed也可。完成时态与过去时态的理解和辨析一直是高考重点，同时也是学生的难点。