In the 1820’s, anthracitecoalfieldsopened 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
答案是E，让在下想不通的是A错哪了。哪位大侠指点一下。。。
而且 E中出口的主语是supply 感觉逻辑不通啊…………作者: Jackjokes 时间: 2012-3-29 11:19
A 错在“there were substantial supplies of coal that was“ that 修饰的是 supplies 应用复数形式were 简言之 就是A of B that ... that 修饰的是A