OG4. The only way for growers to salvage frozen citrus is to process them quickly into juice concentrate before they rot when warmer weather returns.(A) to process them quickly into juice concentrate before they rot when warmer weather returns
(B) to have it quickly processed into juice concentrate before warmer weather returns and rots the fruit
想必大家都曾仔细琢磨过这道题。仅从代词单复数的角度去排除A项，但这样非常危险，一旦出现我不熟悉的单词，那我就必死无疑。后来看OG的解释，才发现before they rot when warmer weather returns与 before warmer weather returns and rots the fruit 在逻辑含义上还是有一些不同的。A项用when 从句，只能表示两个动作在时间上同时发生，而B项将A项中的when从句变成了动宾结构，同时也将这两个事情的逻辑关系从简单的时间关系(同时发生)变成了因果关系。
OG21 Defense attorneys have occasionally argued that their clients' misconduct stemmed from a reaction to something ingested, but in attributing criminal or delinquent behavior to some food allergy, the perpetrators are in effect told that they are not responsible for their actions.
(A)in attributing criminal or delinquent behavior to some food allergy
(B)if criminal or delinquent behavior is attributed to an allergy to some food
OG28. The rise in the Commerce Department's index of leading economic indicators suggest that the economy should continue its expansion into the coming months, but that the mixed performance of the index's individual components indicates that economic growth will proceed at a more moderate pace than in the first quarter of this year.
(编) suggests that the economy will continue to expand in the coming months, and that
(E) suggests that the economy will continue to expand in the coming months, but
OG205. The peaks of a mountain range, acting like rocks in a streambed, produce ripples in the air flowing over them; the resulting flow pattern, with crests and troughs that remain stationary although the air that forms them is moving rapidly, are known as "standing waves."
(C) crests and troughs that remain stationary although the air that forms them is moving rapidly, is
(E) stationary crests and troughs although they are formed by rapidly moving air, is