Which one of the following is not a good demonstration in terms of manners in an academic presentation?
选项：

A:Tap into the potential of your voice to highlight the key points of your, slow down and emphasize the keywords with a raised volume.
B:It’s ok to glance at the screen once in a while, but it’s of paramount importance to have eye contact with the audience when you are presenting.
C:The golden rule in eye contact is that it’s better to look up than down, and it’s better to look around than stare at one spot.
D:It's better to look at the audience all the time when you are presenting because it can let the audience feel that you are very confident about your research.