What could a chair say to deal with the situation when there is awkward silence? There are two proper expressions listed in the choices. Choose all of the correct answers.
选项：

A:May we hear now from some of the participants who haven’t expressed their opinions yet?;
B:No more questions? No? Well, I think I’d like now to turn your attention to our next speaker.;
C:We have gained, through your presentation, a much better insight into….;
D:I think I’d now summarize briefly what has been said so far….