human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Colt model no., Diemaco model, Stock, Fire control, Rear sight, Forward assist, Barrel length, Barrel profile, Barrel twist, Hand guards, Bayonet Lug, Muzzle device
###Question: Which Barrel twist has a Stock of canadian 3rd generation and a Hand guards of short ribbed?
gpt
SELECT Barrel twist FROM table WHERE Stock = canadian 3rd generation AND Hand guards = short ribbed