题目选项分析

The four-million-year-old fossilized skeleton known as Lucy is so small compared with many other skeletons presumed to be of the same species that some paleontologists have argued that Lucy represents a different lineage.

The four-million-year-old fossilized skeleton known as Lucy is so small compared with many other skeletons presumed to be of the same species, and so some paleontologists have argued that Lucy represents a different lineage.