prep sc124 125代词问题 求解！

懒猪笨笨1

124. (31091-!-item-!-188;#058&004372)

Whereas the use of synthetic fertilizers has greatly expanded agricultural productivity in many parts

of the world, an increase in their use can create serious environmental problems such as water

pollution, and their substitution for more traditional fertilizers may accelerate soil structure

deterioration and soil erosion.

(A) an increase in their use can create serious environmental problems such as water pollution, and

their substitution for more traditional fertilizers

(B) an increase in their use can create serious environmental problems like water pollution, and if

substituted for more traditional fertilizers, it

(C) if these fertilizers are used increasingly, they can create serious environmental problems such

as water pollution, and if used as substitutions for more traditional fertilizers, they

(D) the increased usage of these fertilizers can create serious environmental problems such as

water pollution, while if substituted for more traditional fertilizers, this substitution

(E) the increased usage of these fertilizers can create serious environmental problems like water

pollution, while their substitution for more traditional fertilizers

请问各位 正确选项中A中的第一个their 可不可以是指代画线部分前面的“parts”啊
125. (31137-!-item-!-188;#058&004397)

The computer company registered a $16 million net loss for the year, largely because it was

profitable only overseas, where much of their profits were used for paying higher taxes, while

continuing to lose money in North America.

(A) where much of their profits were used for paying higher taxes, while continuing

(B) where much of their profits went to pay higher taxes, as they continued

(C) where much of its profit went to pay higher taxes, while it continued

(D) with much of their profits going to pay higher taxes, while continuing

(E) with much of the profit used for paying higher taxes, as it continued

请问正确选中C中的it 可不可以是指代逗号前面的“profits” 还是说 一个句子中如果出现同一个代词两次，如本句中的it 则它们一定指代同一个东西 指代的东西由第一指示代词决定 应该这样理解吗？
谢谢各位帮助！

懒猪笨笨1

自己顶一个~~

cecilia199004

个人意见 1代词不能指代所有格
2句中未划线部分有it   那后面的it啊its啊都和前面的一致 不会出现指代不清