单选题 1 The cerebral cortex of the human brain is divided into two hemispheres that are linked by a thick band of fibers called the corpus callosum. Each hemisphere has four discrete lobes, and researchers have identified a number of functional areas within each lobe. The left hemisphere has areas for controlling speech, language, and calculation, while the fight hemisphere controls creative ability and spatial perception. This centering of functions in specific areas of the brain is known as lateralization.
2 Much of our knowledge about brain lateralization comes from studies of "split-brain" patients, people with a damaged corpus callosum. In one experiment, a subject holding a key in his left hand, with both eyes open, was able to name it as a key. However, when the subject's eyes were covered, he could use the key to open a lock, but was unable to name it as a key. The center for speech is in the left hemisphere, but sensory information from the left hand crosses over and enters the fight side of the brain. Without the corpus callosum to function as a switchboard between the two sides of the brain, the subject's knowledge of the size, texture, and function of the key could not be transferred from the fight to the left hemisphere. The link between sensory input and spoken response was disconnected.

单选题 Which sentence below best expresses the essential information in the highlighted sentence in paragraph 1 ?

A、 Each half of the brain consists of four types of tissues that are identified by their size and location.
B、 The brain's two hemispheres each have four separate parts, and each part controls several functions.
C、 There are a number of functional centers in the brain, and these can be divided into four main groups.
D、 Research has shown that the brain controls four basic functions, each with a number of variations.

【正确答案】 B

【答案解析】Each hemisphere has four discrete lobes.., is paraphrased in The brain's two hemispheres each have four separate parts researchers have identified a number of functional areas" within each lobe is paraphrased in... each part controls several functions.

单选题 According to the passage, what is one effect of a damaged corpus callosum?

A、 Functions from one side of the brain are transferred to the other side.
B、 People with their eyes open cannot see an object held in the left hand.
C、 The connection between sensory input and spoken response is broken.
D、 Creative ability and spatial perception are greatly diminishe

单选题 Which sentence below best expresses the essential information in the highlighted sentence in paragraph 2?

A、 Information about the key could not travel from one side of the brain to the other because the corpus callosum did not provide the link.
B、 Some people are born without a corpus callosum, so they cannot exchange knowledge between the two hemispheres of the brain.
C、 Both sides of the brain control knowledge of familiar objects, and the corpus callosum functions as a key to that knowledge.
D、 The corpus callosum acts like a computer keyboard in the way that it takes information from the hands and enters it into the brain.

【正确答案】 A

【答案解析】Without the corpus callosum to function as a switchboard between the two sides of the brain.., is paraphrased in ... because the corpus callosum did not provide the link. ... the subject's knowledge of the size, texture, and function of the key.., is paraphrased in Information about the key ... could not be transferred from the right to the left hemisphere is paraphrased in ... could not travel from one side of the brain to the other