OG11-15

15. The Iroquois were primarily planters, but supple­mentinq their cultivation of maize, squash, and beans with fishing and hunting.

(C)and even though they supplemented

(D)although they supplemented

(E)but with supplementing

Grammatical construction + Verb form

The participle supplementing would normally be expected to modify the first clause, describing or extending its meaning, but the logic of this sentence demands a contrast, not an extension. Consequently; the second part of the sentence must be revised to emphasize the contrast properly. The logic of the sentence also argues against a construction that would set the two clauses and the importance of their content equal when they clearly should not be. The best solution is to have the main clause describe the primary activity, and a subordinate clause, although they supplemented, describe the supplementary activity.

B And does not convey contrast; had supplemented is the past perfect tense but the simple past is required to match were

C And does not convey contrast and should be omitted;
                    and even though creates a sentence fragment ,:

D Correct. Using although creates a subordinate clause in this sentence and logically links that clause with the main clause; the simple past
                    supplemented parallels the simple past were.

E But with is awkward and unclear; supplementing is a modifier when a contrasting clause is needed

The correct answer is D.

查过了没人问过，答案选D没有问题,我的疑问的为什么C说and even though creates a sentence fragment ? 请NN帮忙解答一下,谢谢!!

and even though creates a sentence fragment ?

fragment 是为什么产生呢？

噢，想通了。

and后面必需接的是一个完整的句子。even though只是一个从句。