求解这个关于such as 的问题

quasimodov

In the most common procedure for harvesting forage crops such as alfalfa, as much as 20 percent of the leaf and small-stem material, the most nutritious parts of the plant, shatters and falls to the ground.
在这个句子中谓语动词（shatters and falls ）是单数形式，它的单复数形式是受such as后的名词（alfalfa）还是被举例名词（crops）决定呢？
这是不是可以用就近原则解释呢？？
鄙人不才，求NN解答！

genius1824

其实你通过as much as而不是as many as就可以判断要用单数了
主语是 20 percent of the leaf and small-stem material

quasimodov

恍然大悟 谢谢！！