885 section A 21

以下是引用sunmike在2003-11-25 15:14:00的发言：
Over five thousand years ago, archaeologists have discovered that Mesopotamian cooks were preparing chicken with coriander and tamarind, just as Egyptian cooks are still doing today.

(A) Over five thousand years ago, archaeologists have discovered that
(B) Over five thousand years ago, archaeologists had discovered that
(C) Archaeologists have discovered that, over five thousand years ago,
(D) Over five thousand years ago, as archaeologists have discovered it,
(E) Archaeologists have discovered, over five thousand years ago, that

 

从意思上知道选C，但是为什么要用现在完成时啊？哪里可以就看出来啊？是不是一般现在时更好啊！

 Archaeologists discovere that, over five thousand years ago,