C选项：because of是介词，其身后的 drugs that are becoming more expensive和doctors having also written many more prescriptions for higher-cost drugs均为名词短语，这两个名词短语的核心词分别是drugs和doctors。在逻辑上，原因应该是“药物变贵”和“医生开处方”这两件事，而不是药和医生这两个名词，因此本选项是错误的。
实验开始的一个月内吸烟的青少年得抑郁症的概率是不吸烟的青少年得抑郁症概率的4倍，又因为尼古丁可以改变大脑化学物质。所以吸烟导致了青少年的抑郁症。问support
choice a, 在实验开始就已经得抑郁症的青少年，并不会比那些不得抑郁症的青少年，在实验结束之前开始吸烟。correct，排除了因果倒置
Most pre-1990 literature on businesses' use of information technology (IT)—defined as any form of computer-based information system—focused on spectacular IT successes and reflected a general optimism concerning IT's potential as a resource for creating competitive advantage
In the retail industry, for example, in which IT had been widely adopted during the 1980's, productivity (average output per hour) rose at an average annual rate of 1.1 percent between 1973 and 1989, compared with 2.4 percent in the preceding 25-year period.
retail industry的数据是作为例子跟在"productivity paradox"后面
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ABE可以用平行排除
C选项中给Leakey下了定义，说他是一个用xxx来贡献的人，但是句子的意思单纯表明他做出过某些贡献，而不是在下定义，所以选D