Are gray wolves aggressive

no. Some have been able to train wolves. Some wolves can be more aggressive than others and wolves would take way more time to train and it would be harder to take care of them than dogs. Wolves are really more afraid of humans than we are to them! A wolf may attack a human to protect his/her family because it could think the human could hurt or kill the wolves family! Wolves will go to a farm to kill some sheep,cows,goats and others for survival if there's a lack of food and there hungry. Many farmers will kill wolves because of this but wolves are only doing this to survive.