Participants can use the hand symbol in the lower left corner of the video conference to draw attention to themselves when they want to say something.  

The moderator of the video conference can then use the three dots in the participant's tile to "Mute all others" except for this participant. Alternatively, the participant can activate himself to speak using the microphone symbol.

When a person, for example a student, answers, a notification appears on the moderator's screen saying "John Doe would like to speak". A hand symbol is displayed in the student's tile until they no longer respond by clicking the symbol again.