Fact 1: Chordates have a complete digestive system and a closed circulatory system.

Fact 2: All chordates are vertebrates.

Given the two facts above, answer the question "What do all vertebrates have?" with the following options: 
- sensory neurons
 - characteristics
 - a complete digestive system
 - Veins and arteries.
 - sub-units of species
 - wings and feathers
 - gills
 - gizzard


 

   a complete digestive system      