(The list of)( animals that exhibita preference for using either the right or the left hand (i.e., claw, paw, orfoot))( has been expanded)( to include the lower vertebrates)
that是典型的限制性定语从句,说明这些animals的性质而非任意的animals
has 才是list的谓语
-- by 会员 mslancaster (2012/4/7 19:29:57)