- 精华
- 16
- 积分
- 15226
- 经验
- 15226 点
- 威望
- 1520 点
- 金钱
- 5304 ¥
- 魅力
- 3411
|
GWD-11-Q41:
Charcoal from a hearth site in Colorado, 2,000 miles south of Alaska, is known to be 11,200 years old. Researchers reasoned that, since glaciers prevented human migration south from the Alaska-Siberia land bridge between 18,000 and 11,000 years ago, humans must have come to the Americas more than 18,000 years ago.
Which of the following pieces of new evidence would cast doubt on the conclusion drawn above?
A. Using new radiocarbon dating techniques, it was determined that the charcoal from the Colorado site was at least 11,400 years old.
B. Another campsite was found in New Mexico with remains dated at 16,000 years old.
C. A computer simulation of glacial activity showed that it would already have been impossible for humans to travel south overland from Alaska 18,500 years ago.
D. Using new radiocarbon dating techniques, it was proved that an ice-free corridor allowed passage south from the Alaska-Siberia land bridge at least 11,400 years ago.
E. Studies of various other hunting-gathering populations showed convincingly that, once the glaciers allowed passage, humans could have migrated from Alaska to Colorado in about 20 years.
这是WEAKEN题。原文的推理是:木炭是11200年前的(即11200年前由人类活动),而在11000和18000年前之间,冰川在人阻止人类迁到北美。所以人类是在18000年前到达的。其前提是在11000和18000之间,人类无法通过其它途径到达北美。D提出了另外的途径。所以WEAKNE结论。
B错在时间不是campsite的时间,而是REMAINS的时间,这个remains的时间并不代表有人类活动的时间。比如这个remains是什麽更早的古物,是人类从别的地方带来的。所以它的时间不代表人类在北美活动的时间。B错也并不是因为New Mexico无关。B想混淆大家的是:在11000和18000这段时间里,new mexico 也有人住。(因为new mexico 在 colorado的南面,ETS想误导大家16000年时有人通过Alaska-Siberia land bridge)但B并不能weaken原推论。因为即使new mexico 16000有人住,这些人也可能是在18000之前就通过Alaska-Siberia land bridge 搬过来的。
E 人类迁移时间和原文无关。原文只是说11000到18000期间通道都被冰川冰冻,并没说期间有多久解冻,人类可通过 |
|