Citing the recent increase in earnings by several computer companies, economists feel that a cycle has begun in which personal computer users, especially corporate consumers, are replacing their PC’s with more powerful models.
“especially corporate consumers”插入修饰语，应该紧跟在personal computer users，修饰personal computer users。
C there be句型非常的啰嗦，不优选；
D begining的表达没有has begun好；
Choice A: in which ... 跳跃修饰 cycle，表示 “PC 用户将更强的版本取代他们的个人电脑的这个循环”，句子的核心是 “a cycle has begun”，所以，整句话想要表达的是 “PC 用户将更强的版本取代他们的个人电脑的这个循环已经开始了”。因为 cycle 表示的是一段期间，所以 which 指代 cycle，而在 which 前面放一个介词 in，则表示在一段期间。
0 0 回复 2019-11-06 12:34:15
e的 插入语修饰根本就没错 总有人爱乱讲
0 0 回复 2018-12-13 16:23:56
in which 修饰cycle
A. a cycle has begun in which personal computer users OK - The areas of concern were tested, and all were okay. B. a cycle for personal computer users has begun in which they Wrong - Pronoun "They" has no referent. The modifier "for personal computer users" describes the cycle, making the sentence non-sensical. It is not a cycle of users, but a cycle in which users replace their computers. C. there is a cycle beginning for personal computer users Wrong - The prepositional phrase cannot have a verb -- "for... users are replacing their PCs" D. it is the beginning of a cycle for personal computer users Wrong - The prepositional phrase cannot have a verb -- "for... users are replacing their PCs" E. personal computer users are in the beginning of a cycle when they Wrong - Logical predication. Personal computer users cannot literally be "in the beginning of a cycle when they." Perhaps their behavior is in the beginning of a cycle, but not they themselves.
C,D把插入语“especially corporate consumers”去掉的话就变成了there is a cycle beginning for personal users are replacing....一句话中有两个谓语，错误