by the time he reached the dentist ,the pain in his tooth ____A stopped B had stopped C has stoppe
问题描述：
by the time he reached the dentist ,the pain in his tooth ____A stopped B had stopped C has stoppe
D has been stopped 选择哪个?为什么?
不是现在完成的被动吗？疼痛不是被止吗？
答
选择b by the time +句子,主句.这是个固定 句式.从句和主句的谓语的时态有对应关系,从句谓语的时态是一般过去时,主句的谓语的时态是过去完成时.