英文中since 可否与 until 连用

首先确定一个问题 since从句 可以与主句过去完成时 连用
如 I saw Zhang Na last week.We had not seen each other since we parted in Beijing.上周我见到了张娜.从北京分手后我们就再没见过面
其次 until时间状语 可以与 过去完成时连用
所以 本句 since 可与 until 连用 把主句改为 可以延续的过去完成时即可
since the Chinese Exclusion Act was enacted in 1882,America had kept the door closed to Chinese immigrants until 1943.