That的指代问题 疑问

OG128. New hardy varieties of rice show promise of producing high yields without the costly requirements of irrigation and application of commercial fertilizer by earlier high-yielding varieties.

(A) requirements of irrigation and application of commercial fertilizer by earlier high-yielding varieties

(B) requirements by earlier high-yielding varieties of application of commercial fertilizer and irrigation

(C) requirements for application of commercial fertilizer and irrigation of earlier high-yielding varieties

(D) application of commercial fertilizer and irrigation that was required by earlier high-yielding varieties（E）

(E)
                irrigation and application of commercial fertilizer that were required by earlier high-yielding varieties

不是说THAT只能指代单数名词吗?/

OG127. In theory, international civil servants at the United Nations are prohibited from continuing to draw salaries from their own governments; in practice, however, some governments merely substitute living allowances for their employees’ paychecks, assigned by them to the United Nations.

(A) for their employees’ paychecks, assigned by them

(B) for the paychecks of their employees who have been assigned

(C) for the paychecks of their employees, having been assigned

(D) in place of their employees’ paychecks, for those of them assigned（B）

(E) in place of the paychecks of their employees to have been assigned by them

再看下这个，B正确，但是B里面WHO指代的是employees，而和A’s的A一样，A of B的B是不能被指代的啊