28-20: 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.

A: when canals and eventually railroads reached into the region, there were substantial supplies of coal that was

B: once canals and eventually railroads reaching into the region, there were substantial supplies of coal having been

C: with canals and eventually railroads reaching into the region, there had been substantial supplies of coal

D: canals and eventually railroads reached into the region, with substantial supplies of coal being

E: as canals and eventually railroads reached into the region, substantial supplies of coal were

是否选D

这套题,两个小题都选WITH的答案有点怪

我选E，句子结构没什么问题，并且句子重心和题意保持了一直。

D with用法不合适，并且改变了句子重心。

很诧异，为什么大家都在DE项讨论！是因为其他项都有there be吗？

大家要注意，there be不是必然错误！og的解释只是有时把它当作复杂表达！只是矮子里面选高个的时候被淘汰的矮子！

D项是明显错误！with substantial supplies of coal being用来修饰canals and eventually railroads 明显with后的不是canals and eventually railroads 所具有的性质！而且楼上也说了！中心变了！

E项，supplies were exported你们觉得对吗？出口的应该是coal，而不是他的供应吧！~

B的having been时态是不对的！

C的with是没有修饰的！

只有A项虽然there be很罗嗦！但没有任何原则的错误！

此题选A，在我看来，这是铁一样的事实！