21.What is the theme of the talk?
A.The harm of cognitive decline.
B.The approaches to mental health.
C.The advice on our daily activities.
D.The significance of human brains.
22.What is mainly introduced about the speaker?
A.Her personal life.
B.Her cautious character.
C.Her major achievements.
D.Her learning experiences.
23.What can a ticket holder do?
A.Interact with the speaker online.
B.Keep a copy of the recorded lecture.
C.Email Eventbrite for identification.
D.Share his/her link with someone else.