大家请看这个句子:

大家请看这个句子:

however, the camp probably dates to no later than 1630.since no European trade goods were found at the sites, and European traders were active in the region from the 1620's onward.

这句话的逻辑我怎么也看不懂啊, 既然没有发现trade good就说明不在1620左右啊,但是为什么 no later than不晚于1630年呢??这很矛盾啊