himanshukamra2711
acc to me
quesn stem says alfalfa and as much as 20% of the leaf and small stem material of the same crop ie alfalfa,hence it is not a compound subject and the singular subject becomes as much as 20% of the leaf and small stem material ----so singular shatters and falls
Quantity words such as percentages, fractions etc. take up the number (singular / plural / uncountable) of the noun within the of prepositional phrase. For example:
Half of the pizza IS eaten. (countable - singular)
Half of the pizza slices ARE eaten.(countable - plural: one can count how many pizza slices are eaten)
Half of the milk IS eaten. (uncountable: one cannot count half of milk)
In "20 percent of the leaf and small-stem material" the noun (phrase) within the prepositional phrase is "leaf and small-stem material", 20 percent of which is uncountable. Hence a singular verb is required. (one cannot count 20 percent of leaf and small-stem material.)