幾個星期前在語法版發了幾個關于比較結構的問題，up了幾次都沒有人回。這幾天總結了一些notes, 決定貼出來，大家一起切磋。若有錯誤，還望指正!

第一種比較： 同一主語之間（自己與自己）比較

OG 198

198. Although Napoleon’s army entered Russia with far more supplies than they had in their previous campaigns, it had provisions for only twenty-four days.

(A) they had in their previous campaigns

(B) their previous campaigns had had

(C) they had for any previous campaign

(D) in their previous campaigns （E）

(E) for any previous campaign

同一army 的兩件事情比較，than以后的部分可以省略主語及謂語

AC的謂語動詞had補錯, 應該是had had.

92.    Never before had taxpayers confronted so many changes at once as they had in the Tax Reform Act of 1986.

(A) so many changes at once as they had in

(B) at once as many changes as

(C) at once as many changes that there were with

(D) as many changes at once as they confronted in（D）

(E) so many changes at once that confronted them in

同樣一群taxpayers前后發生的事情比較，卻在than后補出了主語及謂語. D的confronted補的完全正確, A中的had就是錯的。另外，D中代詞用了they, 而不是that/those， 因為是自己與自己比。that/those指代同類事物，而不是同一樣事物。

結論：同一主語之間（自己與自己）比較，可以省略主語（因為是自己比自己）及謂語，并且只有當主句也用助動詞,且比較從句的助動詞與主句一致時,才可省略動詞只保留助動詞. 這里特別要考慮時態問題，如過去完成時與過去時比較，若補出謂語動詞，助動詞或動詞的選擇要根據時態來定。若是不省略主語，代詞一般用they/it.

以下的兩個句子than后面雖然都補了had, 但意思完全不一樣。

X had had....than X had... 后面一個had是過去完成時，而非過去時。

X had...than X had...         后面一個had是過去時, 而非過去完成時。

第二種比較：不同主語之間（X與Y）比較

Innits of the Bering Sea were in isolation from contact with Europeans longer than Aleuts or Inuits of the North Pacific and northern Alaska.

（A） in isolation from contact with Eurpoeans longer than
（B） isolated from contact with Eurpoeans longer than
（C）in isolation from contact with Eurpoeans longer than were
（D） isolated from contact with Eurpoeans longer than were （D）
（E） in isolation and without contact with Eurpoeans longer than

D中were絕對要補，否則產生歧義！

isolated from contact with Eurpoeans longer than from。。。補出from

isolated from contact with Eurpoeans longer than were。。。補出were

兩種補出方式（prep. or 動詞）產生的意思完全不一樣，所以要補出were消除歧義。

結論：不同主語之間的比較可以省略謂語動詞，但前提是沒有歧義。我看到網上有些說法，認為實意動詞不能省略，但系表結構就可以。這種說法很片面，所以我特地舉了一個系表結構而不省略的例子。引用一位前輩的話：“。。。ETS如此的reluctant to purport 什么硬性的公理。如何將一個句子表達得準確，簡潔，不產生歧義是ETS對句子改錯的最高要求。有一些通常的做法，但是決不能生搬硬套。”

第三種比較：不同賓語之間（X的a與Y的b）比較
OG 118

The question of whether to divest themselves of stock in companies that do business in South Africa is particularly troublesome for the nation's 116 private Black colleges because their economic bases are often more fragile than most predominantly White colleges.

(A) than

(B) than those of

(C) than is so of

(D) compared to (B)

(E) compared to those of

B中的those指代bases.  than后謂語動詞are省略，因為沒有歧義。

結論：在不同賓語之間比較，一般都會用到代詞，且代詞極少（我不敢制定公理，所以不說“絕對”）出現they/it, 因為雖然是同類，但不是同一樣東西(X的a與Y的b)。謂語動詞的省略根據是否產生歧義而定。