Chordates have a complete digestive system and a closed circulatory system, and vertebrates are members of of a larger group, the chordates . Given these facts, vertebrates have a complete digestive system and a what among the following options:
- Veins and arteries.
 - lack of backbone
 - bruised brain stem
 - critical organs
 - closed circulatory system
 - incomplete circulatory system
 - characteristics
 - sensory neurons


 

     closed circulatory system    