下面哪一种基因的产物不具转录因子的功能？( ) A: bicoid基因产物 B: nanos基因产物 C: caudal基因产物 D: giant产物 E: Kruppel基因产物

According to the location of the nerve in and out of the spinal canal, the spinal cord can be divided into ( ). A: Cervical spinal cord B: Thoracic spinal cord C: Lumbar spinal cord D: Sacral spinal cord E: Caudal spinal cord