题目选项分析

The parachutelike membranes of Africa's scaly-tailed flying squirrels differ from those of the flying squirrels in the family Sciuridae in their attachment to a cartilage rod at the elbow instead of being attached at the wrist.

The parachutelike membranes of Africa's scaly-tailed flying squirrels differ from those of the flying squirrels in the family Sciuridae in that they are attached to a cartilage rod at the elbow rather than at the wrist.