It is reported in the papers that the old coins under the earth for about 200 years by the

问题补充：

It is reported in the papers that the old coins under the earth for about 200 years by the time they were discovered.

A. had buried

B. had been buried

C. buried

D. were buried

答案：

A. had buried

(答案→)B. had been buried

C. buried

D. were buried

解析：本题考察时态。由by the time引导的从句中谓语were discovered知应主句用过去完成时，by引导的时间状语或从句时，主句一般用完成时。