In the 1820's, anthracite coalfields opened in eastern Pennsylvania, and when canals and eventually railroads reached into the region, there were substantial supplies of coal that was exported to the nation's growing mills, forges, factories, and railways.
In the 1820’s, anthracite coalfields opened in eastern Pennsylvania, and when canals and eventually railroads reached into the region, there were substantial supplies of coal that was exported to the nation’s growing mills, forges, factories, and railways.
when canals and eventually railroads reached into the region, there were substantial supplies of coal that was
once canals and eventually railroads reaching into the region, there were substantial supplies of coal having been
with canals and eventually railroads reaching into the region, there had been substantial supplies of coal
canals and eventually railroads reached into the region, with substantial supplies of coal being
as canals and eventually railroads reached into the region, substantial supplies of coal were
我在别的地方看到的,贴给你看一下。。。。。
A. when的错误,when表示发生的同一性,即 A when B,表示恰恰B发生的时候A 发生了。故而A不能用 were表示状态,表达不出when的概念;
B. Once也是强调时间的统一性;having been表示持续到现在的动作,这里没有提及那么就不能应该用having been这个时态;
C. Had been时态错误,表示这个动作在过去已经完结;
D. substantial supplies of coal being无法在逻辑语义上面修饰canals and eventually railroads reached into the region;
E. 正确。
E里面没有that啊。。。。。