The Iroquois were primarily planters, but supplementing their cultivation of maize...
解释中supplementing would normally be expected to modify the first clause, describing or extending its meaning, but the logic of this sentence demands a contrast...这里讲的作用是supplementing的作用还是分词的作用? But the logic of this sentence demands a contrast, 不是已经有but了吗?
The Iroquois were primarily planters, but supplementing their cultivation of maize, squash, and beans with fishing and hunting. supplementing分词省略形式是they supplement而不是they supplemented,时态和were不对