這個是強(qiáng)調(diào)句,是強(qiáng)調(diào)句的特殊疑問句,是對疑問詞進(jìn)行強(qiáng)調(diào).
判斷是不是強(qiáng)調(diào)句的方法是:去掉It is ...that...后,句意及句子結(jié)構(gòu)仍然完整的句子,就是強(qiáng)調(diào)句,
否則就不是.
特別提醒:去掉It is ...that...后,要把被強(qiáng)調(diào)部分還原到原來的位置上.
如問題中的句子去掉It is ...that...后,就成為:What makes them so unhappy?
結(jié)構(gòu)及句意完整,因此What is it that makes them so unhappy?是強(qiáng)調(diào)句.
再如:It is a teacher that my mother is .
去掉It is ...that...后,如果不把a(bǔ) teacher 還原到它本來的位置,那么就成了:
A teacher my mother is .據(jù)此有人說,It is a teacher that my mother is .不是強(qiáng)調(diào)句.
這樣理解就錯了.因?yàn)閼?yīng)該把a(bǔ) teacher 還原到它本來的位置,即:My mother is a teacher.
所以,It is a teacher that my mother is .是強(qiáng)調(diào)句.
又如:It is exciting that we have succeeded in sending up Shenzhou V.
若將It is 及 that同時省去為：We have succeeded exciting in sending up Shenzhou V.
顯然句子錯誤,因此,這個句子不是強(qiáng)調(diào)句型,而是主語從句.十分感謝！很明白！