7. Most archaeologists have held that people first reached the Americas less than 20,000 years ago by crossing a land bridge into North America. But recent discoveries of human shelters in South America dating from 32,000 years ago have led researchers to speculate that people arrived in South America first, after voyaging across the Pacific, and then spread northward.
Which of the following, if it were discovered, would be pertinent evidence against the speculation above?
(A) A rock shelter near Pittsburgh, Pennsylvania, contains evidence of use by human beings 19,000 years ago.
(B) Some North American sites of human habitation predate any sites found in South America.
(C) The climate is warmer at the 32,000-year-old south American site than at the oldest known North American site.
(D) The site in South America that was occupied 32,000 years ago was continuously occupied until 6,000 years ago.（B）
(E) The last Ice Age, between 11,500 and 20,000 years ago, considerably lowered worldwide sea levels.
这道题做了几次总是不太明白。既然考古学家认为首次进入北美是在2000年前，那可以推出在北美发现的遗址最多也就在两千年前，而题干中又已经给出“在南美发现的遗址是在3200年前，那答案为什么又说“在北美发现的遗址都早于南美”呢？这不强词夺理吗？
