A、It is valuable for interpreting complicated dreams. B、It is not very helpful for interpreting complicated dreams. C、It is usef

Scientists think it will be possible to record people’s dreams and then interpret them, according to a new report. They claim to have developed a system which allows them to record higher level brain activity. Dr. Moran Cerf told the journal Nature:" We would like to read people’s dreams. "
    (29) Previously the only way to access people’s dreams is for psychologists to ask about them after the event and try to interpret them. But Dr. Cerf told the BBC: "There’s no clear answer as to why humans dream. And one of the questions we would like to answer is when do we actually create this dream. "
    The scientist believes his latest research shows that certain brain cells are linked with specific objects or concepts. He found that a particular cell lit up when a volunteer thought about Marilyn Monroe. (30) If a database was built up identifying various cells with concepts and objects,it would allow them to "read the subject’s minds" .according to Dr. Cerf.
    (31) However,Dr. Roderick Oner,a clinical psychologist and dream expert,said that this method would be of limited help when it came to interpreting complicated dreams. In addition to get a detailed picture of individual cells subjects had to have equipments implanted deep in the brain using surgery.
    However,Dr. Cerf said he hoped that it would be possible at a later stage to monitor people without invasive surgery. He said it would be "wonderful" to be able to read the minds of coma patients who are unable to communicate.
29. What did psychologists use to do if they wanted to access people’s dreams?
30. According to Dr. Cerf, what is the function of the database?
31. What does Dr. Roderick Oner think of Dr. Cerf s method?