that is to say, it is to your best advantage to enlist your
best speaker for the presentation. i recommend that you relay this
task to only one person. if you insist on having two people speak
during the half hour, so be it, but avoid designating more than two
people. you lose a lot of time in context switching and the
presentations turn out to be much less coherent if you switch every 10
minutes (or less!).
on the other hand, it is perfectly acceptable for the entire
project group to respond to questions from the audience. this is not a
task restricted to the speaker. questions are best answered by the
group member most familiar with that part of the project under
discussion.
we look forward to finding out more about your interesting
projects. good luck.
Nadia