英语句子英译汉的问题Butitwassoslowandwastefuloffuelthatitcouldnotbeemployedoutsidethecoalminesforwhichithadbeendesigned.这句话的forwhichithadbeendesigned部分为什么可以翻译成：这与最初的设计

Question

英语句子英译汉的问题
But it was so slow and wasteful of fuel that it could not be employed outside the coal mines for which it had been designed.
这句话的for which it had been designed部分为什么可以翻译成：这与最初的设计期望背道而驰?
for which it had been designed

Answer 1

但是他很慢又很浪费燃料,所以他不能再煤矿外使用,for which it had been designed.
在这里他的意思是 （这东西）原本是设计好让人们可以在煤矿外使用,但是因为他太慢又浪费燃料,所以他“与最初的设计期望背道而驰”.