A land of diversity
最早一批人具體是在什么時候來到我們現在了解的加利福尼亞地區的，誰也說不清楚。
what we now know as california是一個由what引導的名詞性從句，作arrive in的賓語, what是復合關系代詞，相當于the thing(s) that。因此，在名詞性從句中可以用the thing(s) that取代的，只能用what。
聯想拓展
①名詞性從句中what與that的區別：that在名詞性從句中不作句子成分，what必須作句子成分。
②名詞性從句中what與which的區別：指代前文已經提到過的對象或范圍時，用which，否則用what。
what he said sounds reasonable.
他說的聽起來有道理。(what作said的賓語)
that our team has won the game has been proved.
已經證實我們隊贏得了比賽。
(that在主語從句中不作句子成分)
there are many books available. i don t know which to read.有許多書可供閱讀，但我不知道讀哪一本。
(which指的是前文提到的books中的一本)
what book do you want to buy?
你想買哪種書？(沒有提及買什么書或哪一類書)
高手過招
選詞填空（that/what） （原創）
①this is he wanted.
②this is the thing he wanted.
③she is no longer she used to be.
④she is no longer the person she used to be.
答案： ①what ②that ③what ④that