I now turn to Freud ,from whose work the following quotation is taken.
后半句 其實(shí)應(yīng)該反過來來理解 the following quotation is taken from whose work.這里的whose其實(shí)就是前句的Freud.
這種句子你就把句子按陳述語氣讀一下,就是說 要調(diào)換前后位置.就知道要不要加in on from這些介詞了
比如：He is the person that I make friends with.這里 詞組就是make friends with somebody,少了with這個(gè)介詞,這個(gè)詞組就不存在了,這句話就有問題了.
這是最通俗最好理解的解釋了