Listening is as important as speaking.
To listen out the opinions is important. Value judging the opinions may cause a little imbalance in class. Do not value judge and give your nod to any opinion. It may create a notion in students to feel that they may be are wrong.
It's important you let everyone share their opinions. Teacher's judgment gives out the notion that there's right and wrong. While voicing out opinions, one doesn't need to know what's right and wrong. That may stunt their expressions in the class.