tt gwd17-18

------------------------------------------------------------------------------------------------------------

18. GWD17-Q18:

Over the course of the eighteenth century, the average output of ironwork tripled as a result of several improvements in blowing machinery and because coal replaced charcoal as the fuel used in the smelting of iron ore.

1. Over the course of the eighteenth century, the average output of ironwork tripled as a result of several improvements in blowing machinery and because coal replaced charcoal as the fuel used in the smelting of iron ore.
2. Over the course of the eighteenth century a tripling in the average output of ironwork was due to the replacement of charcoal by coal for the fuel used in the smelting of iron ore, in addition to several improvements in blowing machinery.
3. With charcoal’s being replaced by coal as the fuel used in the smelting of iron ore and several improvements in blowing machinery, the average output of ironwork tripled over the eighteenth century.
4. The replacement of charcoal with coal for the fuel used in the smelting of iron ore and several improvements in blowing machinery, the average output of ironwork tripled over the eighteenth century.
5. Charcoal being replaced by coal as the fuel used in the smelting of iron ore, and several improvements in blowing machinery, which tripled the average output of ironwork over the course of the eighteenth century.

The key is C but I really doubt about "with charcoal's being replaced".

A is not parallel, so I chose B.

Any help, thx !

A,虽然形式上不平行，但意义平行，剩下的错误严重

thx for reply, I guess A is the best we can go with so far.

选A的兄弟，能不能回答一下and because中的and连接的是谁？如果是单纯的连词，and because前必须加逗号，这是og里说了一百遍的东西

呵呵，比较两个小黑谁更白的题。。

uuuuuuup!

我也选的B，为什么是A呢，我可以理解A的结构不平行，但是意义是平行的。可是B的意思难道错了么？还是另外有什么原因的