(47) He asserted, also, that his power to follow a long and purely abstract train o

(47)Heasserted,also,thathispowertofollowalongandpurelyabstr acttr ainofthoughtwasverylimited,forwhichreasonhefeltcertainthathenevercouldhavesucceededwithmathematics.此处译文为：

正确答案：
Heasserted,also,thathispowertofollowalongandpurelyabstr acttr ainofthoughtwasverylimited,forwhichreasonhefeltcertainthathenevercouldhavesucceededwithmathematics.
本句考查点是宾语从句，非限制性定语从句。主干是Heassertedthat…。宾语从句的结构是hispowerto…was…。其中不定式to引导的部分follow…ofthought做power的定语;forwhichreason所引导的非限制性定语从句中又包含一个that引导的表语从句。
参考译文：达尔文同时声称，对于冗长而且纯抽象的思想，自己的理解能力并不强。因为这个原因，他相信自己在数学方面根本不会成功。