____are playing an important part is well known to us all.
A.That who
B.Who that
C.Who
我的理解A中that引導(dǎo)主語從句,而who引導(dǎo)定語從句修飾that
B中Who引導(dǎo)主語從句,that引導(dǎo)定語從句修飾who
C中who引導(dǎo)主語從句.
答案是C,求前兩種理解錯(cuò)誤之處.
答：這是一道有問題的人工考題.
析：本題考查的是名詞性從句的主語從句.謂語是is well known to us all.
從謂語的表述來看,主語從句應(yīng)為一個(gè)事實(shí),多為由that引導(dǎo)的一個(gè)陳述句變過來的主語從句,如：That the earth goes around the sun is well known to us all.
譯：地球繞太陽轉(zhuǎn),這件事我們大家都知道.
Who are playing an important part 是一個(gè)特殊疑問句,是一個(gè)問題.不是陳述句,不是一個(gè)事實(shí),所以不用that-引導(dǎo)名詞性從句.而直接可以用連接代詞（副詞）即wh-詞引導(dǎo)名詞性從句.這個(gè)名詞性從句由特殊疑問句變來,還帶有疑問的意思,如作主語,系表常為：is not clear,is still unknown之類的.如
Who will be our new English teacher is not clear/ is still unknown.
誰將是我們的新英語老師（這個(gè)問題）現(xiàn)在還不清楚.（仍不知道）.
當(dāng)然,what,when,where,why這三個(gè)連接代詞和連接副詞,除了引導(dǎo)由特殊疑問句變來的名詞性從句外,還可以引導(dǎo)一個(gè)相當(dāng)于一個(gè)名詞+定語從句的純名詞（無疑問意義）的名詞性從句.
如：What he said is important.=The thing that he said is important.(所說的話,不是“什么?”）
When he joined the army is known to us all.=The time when he joined the army is known to us all.（參軍的時(shí)間,不是“何時(shí)?”）
This is where Luxun was born.=This is the place where LuXun was born.(出生地,不是“在哪里?”
That's why he was late.=That's the reason why he was late.(理由,不是“為什么?”）
Whatever,whoever 這兩個(gè)詞,可以引導(dǎo)純名詞性從句=anything that-從句和anyone who-從句
如：Whoever breaks the law should be punished.=Anyone who breaks the law should be punished.
任何一個(gè)犯法的人（不是“誰”）.
照理who與what一樣,除了引導(dǎo)由特殊疑問句變來的名詞性從句外,也能引導(dǎo)純名詞性的從句的.可實(shí)際上除了whoever引導(dǎo)的純名詞性從句外,很少見到由who引導(dǎo)的這類名詞性從句.
本題句就是想作這方面的嘗試.
即使可以這樣who=the person(s),則這一題句的主謂一致問題沒有解決好.
如果純名詞性的主語從句Who are playing an important part =the persons who are .,則主語是一個(gè)復(fù)數(shù)概念.與is well known不一致.
如果是一個(gè)問題,則系表應(yīng)改為：is not known yet.之類的：
Who are playing an important part is not known yet.
譯：誰正起到一個(gè)重要的作用,這個(gè)問題現(xiàn)在還不知道.