In the research, Chang used the devices to record brain activity while each patient was asked questions. Using the recordings, Chang and his team built computer models that learned to match particular patterns of brain activity to the questions the patients heard and the answers they spoke. Once trained, the software could identify almost instantly, and from brain signals alone, what question a patient heard. It was accurate 76 percent of the time.
The work is still in its early stage. However, Winston Chiong, a scientist, said it was important to debate the moral problems such systems might raise in the future. For example, could such speech- devices by accident reveal people's private thoughts? Chang said that sharing their people's inner thoughts is almost impossible. His device works only as thoughts are turned into signals to drive muscles involved in speech. \communicate and can't, I think we have a responsibility as scientists to restore that.” He said. 28．Why does the writer mention Stephen Hawking? A．To introduce a breakthrough in communicating. B．To show honor to the famous scientist. C．To reflect his difficulty in speaking. D．To explain his special way of making sound. 29．How does the brain-reading software work?
A．By sensing the sound wave of words. B．By receiving brain signals. C．By moving muscle suddenly. D．By picking up eye movements. 30．What does the underlined word \
A．Remove.
B．Cover. C．Expose. D．Change.
31．What is the main idea of the text?
A．The patient communicates with doctors freely. B．A new software follows your words meanwhile. C．Others may read your inner thoughts.
D．Brain-reading software helps the p