Depending on the structure of your presentation you may want to ask if you audience has any question. There are a couple of ways to ask for question from your audience. A lot of presenters will ask the following to the audience:
“Do you have any questions?”
This is not necessarily the best way of asking for question. The way this question is formulated is seeking for a yes / no type of response. It is like a closed type of question. It is better to ask an open question that triggers interaction. Therefore you can better ask:
“What questions do you have?”
The way this is formulated presumes that your audience has questions and opens the floor to actually ask the questions. If you ask it like this it will be more inviting to your audience to ask questions. You may want to have a look in the book that is part of the Public Speaking Kit as it includes an entire section with tips and tricks about how best to respond to question.