11. In the most common procedure for harvesting forage crops such as alfalfa, as much as 20 percent of the leaf and small-stem material, which is the most nutritious of all the parts of the plant, shattered and fell to the ground.
(A) which is the most nutritious of all the parts of the plant, shattered and fell
(B) the most nutritious of all parts of the plant, shatter and fall
(C) the parts of the plant which were most nutritious, will shatter and fall
(D) the most nutritious parts of the plant, shatters and falls（D）
(E) parts of the plant which are the most nutritious, have shattered and fallen
答案选D,但是我觉得谓语动词应该是复数形式呀, 因为X percent of Y,不是应该看后面的名词的形式吗?如果后面是不可数名词就用单数谓语动词,反之则用复数形式动词,这道题,我不知道LEAF和MATERIAL是不是可数名词,但是是两种加起来,我觉得应该是复数吧??? | 
