petroleum is to industry what blood is to man.
石油对于工业就如同血液对于人体
sth is to sth What sth is to sth
特殊句型,固定的,记住就好!
a new factory has been built in what was a wasteland.
新工厂建在曾经是一片废墟的地方.
what was a wasteland在句子中作宾语,多以不能用that 或是 which
用where可以这样说
a new factory has been built in where it was a wasteland.