A、Hawking made a face-to-face chat with the audience at the Hong Kong Science Park. B、Hawking used technology to transmit his di

"Could you hear me?" Stephen Hawking asked in his iconic computer-synthesized voice, getting a cheerful "yes" from hundreds of people in a speech hall at the Hong Kong Science Park.
    "I can hear you, too," in seconds he replied, this time triggering from the audience even more exclamations; "Wow!" "Cool!"
    This dialogue on Friday night appeared to be a face-to-face chat, but according to the organizer, Hawking was actually sitting in front of a green screen in his office in Cambridge, only having his image beamed to a transparent screen in the hall in Hong Kong and presented to the audience as a digital human hologram—a kind of photograph made with a laser that looks as if it is not flat when you look at it from an angle.
    In the over-one-hour speech, Hawking talked about his life experience and research progress, shared his views on topics from the beginning of time to Brexit, and encouraged the audience to tackle difficulties in life just as how he did.
    The speech included a touching account of the world-famous physicist’s early life, as well as flashes of his sense of humor.
    Talking about how he almost lost confidence in life after he was diagnosed with a motor-neuron disease but regained momentum for continuing his research after meeting his future wife, Hawking said: " If I want to get married, I need to finish my PhD and get a job. "
    When referring to his bestselling book A Brief History of Time, he joked; "l am sure you have all read it from cover to cover, so I shall be asking questions later. "
    This virtually-delivered speech was realized thanks to the augmented reality holographic technology, or Huma Gram, as called by the developer ARHT Media on its website.
    ARHT Media, in cooperation with Chinese Internet game developer Net Dragon, demonstrated the technology for the first time in Hong Kong.
    ARHT Media President and CEO Paul Duffy said he hoped to use this technology to "bring" more outstanding figures to Hong Kong and provide inspirations for citizens here.
    Questions 23 to 25 are based on the recording you have just heard.
    23.What can we learn about Hawking’s talk in Hong Kong?
    24.What did Hawking talk about in the speech?
    25.What did Paul Duffy, ARHT Media President and CEO, hope to do?