1. According to Interstudy, a nonprofit organization that studies health maintenance organizations (HMO’s), they estimate that, in comparison to last year, when only 36 percent of the nation’s 607 HMO’s was profitable, this year 73 percent will be. (A) they estimate that, in comparison to last year, when only 36 percent of the nation’s 607 HMO’s was profitable, this year 73 percent will be (B) compared to only 36 percent of the nation’s 607 HMO’s being profitable last year, they estimate 73 percent would be this year (C) only 36 percent of the nation’s 607 HMO’s were profitable last year; it estimates that this year 73 percent will be (D) it estimates 73 percent of the nation’s 607 HMO’s would be profitable this year; last year that was only 36 percent（C） (E) only 36 percent of the nation’s 607 HMO’s last year were profitable, whereas they estimate it this year to be 73 percent 大全的解释是： 46, sec13-09 A) they应该是it指Interstudy。only 36 percent of the nation’s 607 HMO’s was，was应该是were, 因为HMO’s是复数。
B) being错没必要，they应该是it指Interstudy。
C) best D) would时态和estimates不一致，will好。that指代不明确。
E) they应该是it指Interstudy, 后面的it没有明确指代。
我的问题是黄色高亮的部分说的对么？虽然HMO是复数，但前面的中心词是percent，单数啊，应该用was还是were？ | 
