题目：
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：
B。
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。
