Answer
If students have questions during a Zoom-meeting, they can for example turn on their microphone and ask the questions.
Alternatively, students can post their questions in the chat. Questions posted in chat can either be answered right away or collectively at the end of the Zoom-meeting.
In this case, it is helpful that one person collects all questions posted in the chat, in order to keep an overview of them. In advance the lecturer is not interrupted all the time.
In the How-Tos and Instructions area of the Distance Learning Good Practice page in the TU coLAB, you can find further helpful Tips for Online-Lessons with Large Numbers of Participants.