主語就是than，你可以把than看作帶有比較作用的that，這樣應(yīng)該會(huì)好理解點(diǎn)

Q1:  誰是它的主語？

  A1:  主語 = treatments (復(fù)數(shù)), 所以 than ARE (復(fù)數(shù))


Q2: 為什么感覺  than are possible 缺主語？

  A2: 直述 = treatments THAT provide more detail than space** allotted for this introduction here would allow = treatments THAT are more detailed because ....

    THAT 后面的字串描述 THAT 前面的主題 ( 通常是,但不總是緊接 THAT 之前的字 ), THAT 起代名詞作用, 經(jīng)常緊跟主題, 實(shí)際上可有可無**

    ** space WHICH IS allotted for = space allotted for       space (單數(shù)) 配 which (單數(shù))

============

不是  are possible,  是 THAN are possible

引用回帖:

5樓: Originally posted by Fantein at 2016-10-06 10:25:39
感謝回答！
大致懂了，是省略的一種吧…
?… a set of further readings which will provide you with more detailed treatments than (treatments/those) are possible in this introduction.
這樣寫是完整句子？
...

... a set of further readings which will provide you with more detailed treatments than those THAT are possible in this introduction

  NO:  ... more detailed treatments than treatments   (忌諱重復(fù))

YES:  ... more detailed treatments than those  ( 第二次提 "treatments"   用 "those" )    <=  treatments / those (復(fù)數(shù)), 所以用 that 不用 which (單數(shù))
，

引用回帖:

7樓: Originally posted by wang8102 at 2016-10-06 15:17:02
that 做主語還能省略? than的詞性有兩種，一種是介詞一種是連詞(可連接兩個(gè)名詞，或者從屬連詞鏈接兩個(gè)句子)，明顯不是介詞，作為連詞鏈接句子后面缺少主語，而主語在句子里是不能省略的，所以個(gè)人認(rèn)為是句子吧tha ...

應(yīng)該不可能是寫錯(cuò)了，這句話出自劍橋大學(xué)出版社原版教材。