He is____ is known as a hacker ---he likes showing off on th

高一英语 一题单项选择 详细解释一下
He is____ is known as a hacker ---he likes showing off on the internet and attacks websites.
A.what B.who C.that D.who
答：A
译：他就是所谓的黑客--他喜欢在网上出风头,攻击网站.
分析：what从句是一个名词性从句,what=the+名词+that-定语从句.此句为出题而造,对初学者的理解句意会造成难.其实在理解句意时,可将what seems to be,what is,what is known as之类的略去不看,将句子简化,这句就相当于：He is a hacker--...因为what-从句有时候就相当于一个名词.如after what seemed (to be) half an hour.就可以直接理解为after half an hour的另一种表达.后者为准确（半小时之后）,前者为模糊（在过了似乎是半个小时之后）,如不为考试,改成after about half an hour完全可以.

what 职业

这是一个表语从句，who is known as a hacker整个做is的表语，hacker是人，故用who.

选A,因为这里的what就等于a person who 因为这里没有先行词 所以不能用who 如果这里有一个先行词person就可以用who了

选A
what相当于一个先行词加一个that，也就是he is one that is known as a hacker.
he is后加一个表语从句（宾语从句）is后缺个宾语，所以我们用what
如果前面是he is a man___后面就得用that或者who了
也就是说that和who引导表语或宾语从句的时候，前面要有个先行词走在它们前面开路的
而w...