标题: 请教NN，什么时候要对比？ [打印本页] 作者: fornow 时间: 2011-2-6 04:16 标题: 请教NN，什么时候要对比？ Recently implemented "shift-work equations" based on studies of the human sleep cycle have reduced sickness, sleeping on the job, fatigue among shift workers, and have raised production efficiency in various industries. (A) fatigue among shift workers, and have raised (B) fatigue among shift workers, and raised (C) and fatigue among shift workers while raising (D) lowered fatigue among shift workers, and raised (E) and fatigue among shift workers was lowered while raising
答案是C 选A就错在没有用while表示对比？
什么情况下要注意突出对比？
207. In the textbook publishing business, the second quarter is historically weak, because revenues are low and marketing expenses are high as companies prepare for the coming school year. (A) low and marketing expenses are high as companies prepare (B) low and their marketing expenses are high as they prepare (C) low with higher marketing expenses in preparation (D) low, while marketing expenses are higher to prepare (E) low, while their marketing expenses are higher in preparation