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 that they have presumed to be of the same species, so that some paleontologists have argued that Lucy represents a different lineage.