15. The Iroquois were primarily planters, but supple mentinq their cultivation of maize, squash, and beans with fishing and hunting. (A)
but supplementing (B)and had supplemented (C)and even though they supplemented (D)although they supplemented (E)but with supplementing 答案D。 我的疑问在A选项。 OG解释只是在强调supplemented才是正确表达句子意思的分词，另外逗号两边表示转折，但没有说明but后面不接句子是错误的。 于是我产生疑惑，but之后是否能接分词结构呢？but是用来表示转折的。
我个人感觉上是不行的。好像做了这么多题还没有遇到过but之后能够接分词结构的。向各位请教意见！更希望大家能够提供实际例子～谢谢大家～ | 
