大全 985 疑问

eshopaholic

1.       Those who have visited theGrand Canyon have typically seen layers of sediment in the gaping canyon,with different colors that mark the passage of time like the rings in atree trunk.
(A) seen layers ofsediment in the gaping canyon, with different colors that mark
(B) see layers ofsediment in the gaping canyon, whose different colors mark
(C) been seeinglayers of sediment in the gaping canyon, whose different colors are markers of
(D) been able tosee layers of sediment in the gaping canyon, with different colors marking（D）
(E) seen layers ofsediment in the gaping canyon, marking by different colors
答案D。哪位能详细解释下。谢谢

sgwconfident

BC首先排除，记住, 后面只跟which就对了；E排除，句意明显不对，marking的动作发出者也不可能是those；D比A简洁而且表述清楚（你不觉得如果用seen的话感觉不太舒服吗），能用分词修饰的不用从句...

提供一种思路（也有可能解释的不对，欢迎大牛清拍）

eshopaholic

我的问题在于，为什么要用be able to？ 感觉这个涉及对句子逻辑的理解，也是近来的考试趋势

eshopaholic

请大家指点下。谢谢