19. The Iroquois were primarily planters, but supplementing their cultivation of maize, squash,and beans with ?shing and hunting.
(A) but supplementing
(B) and had supplemented
(C) and even though they supplemented
(D) although they supplemented
(E) but with supplementing
我想问一下为什么A不行呢?答案上说supplementing的错,为什么?难道ing形式表达不了转折么?谢谢啊……
-- by 会员 tjtgzxs (2011/10/2 15:34:06)