郁闷语法题！！！

以下是引用寂寞的自由在2004-2-18 5:44:00的发言：
during the nineteenth century Emily Eden and Fanny Parks journeyed throughout India, sketching and keeping journals forming the basis of news reports about the pricely states where they had visited.



A) forming the basis of news reports about the princely states where they had visit


B) that were forming the basis of news reports about the princely states


C) to form the basis of news reports about the princely states which they have


D) which had formed the basis of news reports about the princely states where they had


E) that formed the basis of news reports about the princely state they


答案是E，自由不明白这个题到底考什么知识点，而且对因为什么对，每个选项错在哪里了？痛苦！！！

以下是引用寂寞的自由在2004-2-18 16:12:00的发言：
谢谢大家，可是visit也有不及物动词啊，我查字典了，所以where的用法不错哦？



in addition, "during the nineteenth century ”表示一段时间，同进行时不是很好的匹配吗？谢谢大家帮助水平低低的自由