1......
draw up: 签署
2......
draw back: 倒退
3......
draw up=stop: 停止,停下来
Summary writing
1......
1 The tunnel will(would) be ventilated, a French engineer planned to build in 1858.
The tunnel which a French engineer planned to build in 1858 would be ventilated if tall chimmeys were built above sea level.
先行词, which : 非限定性定语从句
The tunnel, which a French engineer planned to build in 1858, would be ventilated if tall chimmeys were built above sea level.
3 because they would
4 Though...because...
because the British had feared invasion.
It was stopped because the British had feared invasion.
Though it was begun (work begin forty-two years later), it was stopped because...
5 However 起了副词的作用,后面可以直接加一个句子
Composition
1 Thanks to : 幸亏(to是介词) / because of : 由于
Thanks to the English Channel which separates British from Europe, the country has not been invaded since 1066.
2 now that : 即使 (既然)
Howwever, now that moden warfare is far more complex ,such fears no longer exist.
即使现代战争越来越复杂了,然而这样的害怕都已经不存在了
3 Both...and...