You can take the initiative to talk to them, because college roommates are actually the most familiar people in the university, and they have lived together for four years. They didn't talk to you at first, probably because everyone didn't know much about it. It's good to get familiar with it. You can try to break the deadlock. If they don't talk to you and you don't talk to them, it will lead to a vicious circle. But if someone breaks the deadlock, the atmosphere will gradually improve. For example, you can invite them out to play, eat and have a picnic, or go to an amusement park or ski. Because group activities can enhance each other's feelings, you can try your best to help them when they are in trouble, live in a dormitory, and don't let yourself become trouble to others. Just pack your things and pay attention to personal hygiene. Being too sloppy will give a bad impression.