问题：
[多选题]A keynote speech ______________.
Ashould capture the central theme of the conference
Bis usually given by well-known experts in a particular field
Cis usually given in parallel session
Dis usually one of the highlights of a conference
[多选题]A keynote speech ______________.
Ashould capture the central theme of the conference
Bis usually given by well-known experts in a particular field
Cis usually given in parallel session
Dis usually one of the highlights of a conference
