请教新东方软件上的一道题：

sunyutong

Although some officials noted that using machines for farming in China costs more than traditional hand cultivation, the mechanization of farming in the village of Long Bow doubled the corn yield while the previous year's costs were cut in half.

A mechanization of farming in the village of Long Bow doubled the corn yield while the previous year's costs were cut in half.
B mechanization of farming in the village of Long Bow doubled the corn yield while cutting costs to half those of previous year.
C mechanization of farming in the village of Long Bow doubled the corn yield as costs were cut to half of the previous year's
D farming mechanization in the village of Long Bow doubled the corn yield as it cut in half the previous year's costs.
E farming mechanization in thw village of Long Bow doubled the corn yield while costs were cut to half that of the previous year.

正确答案是B. 能问一下 half 在句子中充当什么成分吗? 总觉得怪怪的. 不如half of those of precious year 那么自然. 多谢了!

1stzhang

我是这样解题的，供参考：
（1）一看5个选项长的差不多，主干没有严重问题，马上开始比较答案
（2）比较a/b，A的意思是不对的cut in half是”一分为二“,保留B;
        比较c/d，c的这种结构 half of the previous year's 就是错误的象征
        d也是cut in half;
（3）最后比较b/e,b/e有两个区别（1）that 和those;（2）分词短语和被动形式的从句；任何一个都有理由放弃e,选择B

sunyutong

分析得挺有道理的。很敬佩的说！
没几天就要考试了，可语法还是一团迷雾，心慌慌的说！

patrick

我觉得可以从并列关系上排除其他的答案

1stzhang

我给你个建议拿出5个section,前面的题目4个section,后面的老题一个section.用统一的思路把5个section全做一遍，把思路理清楚。