题目选项分析

RON:remember that you're looking for REQUIRED ASSUMPTIONS.here's a very useful criterion to use in these problems:
try REVERSING putative assumptions and see the effect on the argument.
if you REVERSE A REQUIRED ASSUMPTION, the ARGUMENT SHOULD BECOME INVALID.let's try this with your top 3 choices:(b)
reverse this assumption: let's say all the species are indigenous to some common region.
this doesn't destroy the argument; it's perfectly consistent with the idea of traveling artisans (who presumably would have come from that common region).
wrong answer.(d)
reverse this assumption: let's say that there are some animal figures that are not readily identifiable.
this has no effect whatsoever on the argument, which is concerned only with some of the animal figures (i.e., the ones that weren't native to the local area).
wrong answer.(e)
reverse this assumption: let's say there was a common repertory of mosaic designs.
in this case, that repertory - since it was a common repertory - would have included animal figures from all over the place. (at the very least, it would be quite unreasonable to expect a common repertory to have been restricted to animal figures from the sepphoris area in particular.)
this destroys the argument, because, were there such a repertory, then artists local to sepphoris would have followed it as well, creating the exotic designs despite their status as natives in th

不存在一本目录 大家都会看的这个目录
所以取反之后削弱

结论：mosaics是traveling artisans带来的
住在不同地方的 artisans 创造的mosaics不一样，没有共同点。
如果有共同点，那说明可能不是其他artisans带来的而是当地的artisans创造