Fact 1: Most invertebrates have a nervous system.

Fact 2: Insects are the most common invertebrates.

Given the two facts above, answer the question "most insects have a what?" with the following options: 
- a cuticle
 - storing system
 - city system
 - epidermis and dermis
 - nervous system
 - building system
 - four limbs
 - layers of fat


 

     nervous system    