两道SAT语法题和一道词汇题!

题目

两道SAT语法题和一道词汇题!
1.Although the writer had intended to conceal the criminal's identity until the final chapter,he planted obvious clues to the identity earlier in the book,(and he thus had underestimated the reader's intelligence).答案是thus underestimating the reader's intelligence,请问原文错在哪里?and thus不是有这种表达吗?
2.Spotted knapweed,(rapidly infests rangeland throughout the western United States,is an invasive thistleplike plant native to Siberia and central Europe.)答案是an invasive thistle-like plant native to Siberia and central Europe,is rapidly infesting rangeland throughout the western United States.原文错在哪里?而且我觉得这个答案反而改了句子所要陈述的重点.
3.While the manager clearly sought to ____ the optimisn of the marketing team,she stopped short of pronouncing their plan unfeasible.答案是填temper,为什么不能填rekindle?

答案

1、如果不用thus doing形式,应该改成 and thus he underestimated...,一是从逻辑关系看,thus应该在he之前,二是从时态看,这里描述的东西并非发生于前文的planted之前,不宜使用过去完成时.2、原文错在infests,以谓语动...