高中完型英语题
Hefinallyagreed.SoIwasabletocleanhishouseandwashhisclothes.Idiscoveredabeautifullamp,coveredwithdust,butstillattractive.OnlyGodknowshowmanyyearshadpassed()helastlitit.
选项中有after和since
请问为什么选since不选after.
从句是after引导主句可以用完成时吗?
前面的knows为什么是一般现在时?