2012gre作文大讲堂:Issue写作范文详细解析(15)
本文主要讲解GRE作文相关内容,希望能帮助童鞋们提高写作能力。留学群liuxuequn.com编辑部敬上。 As people grow older, an enzyme known as PEP increasingly breaks down the neuropeptide chemicals involved in learning and memory. But now, researchers have found compounds that prevent PEP from ...