单选题 Many psychologists in the early twentieth century believed that humans use only 10 percent of their brains, and even the great Albert Einstein once wrote that most people use only a small portion of the grey matter between their ears. It's a theory that has often been put forward in television documentaries, magazines, advertisements and books over the past century. But nearly all scientists now agree the 10 percent theory is completely unfounded . In fact, they question how this figure was ever arrived at in the first place and what areas of the brain are supposed to be unneeded. The theory supposes that if 90 percent of the brain were removed, a person would still be able to function normally, while in reality it is known that damage to even a small area of the brain can result in extremely serious physical injuries and that many areas of the brain are used at the same time for some complex activities or thought processes. Throughout the course of one day, most areas of the brain are active at some time, even during sleep. The 10 percent theory suggests that certain areas of the brain are not used, but scans slow activities throughout the entire brain and not in any separate part. The final argument against the 10 percent theory is the fact that doctors carefully map the brain before removing brain cancers so that they don't affect other essential areas. From an evolutionary point of view, it's highly unlikely that our comparatively larger brains would have evolved from our ancestors if the extra areas were not needed. In fact, there is absolutely no evidence to support the 10 percent theory.

单选题 How did the 10 percent theory get such widespread popularity?

单选题 The underlined word "unfounded" is closed in meaning to "______".

单选题 Which of the following is TRUE according to the writer?

单选题 What can we infer from the passage?

单选题 What is the main purpose of the passage?