21.   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

(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,（C）

(E) Archaeologists have discovered, over five thousand years ago, that

怎么可能是C呢，诶，傻了

考古学家现在已经发现：5000年前。。。。。。。。

5000年前是修饰后面的，不是修饰考古学家