题干

如图,反映的是某中学九(1)班学生外出乘车、步行、骑车人数的扇形分布图,其中乘车的学生有20人,骑车的学生有12人,那么下列说法正确的是(  )

 

A:九(1)班外出的学生共有42人                  

B:九(1)班外出步行的学生有8人

C:在扇形图中,步行学生人数所占的圆心角的度数为82°

D:如果该中学九年级外出的学生共有500人,那么估计全年级外出骑车的学生约有140人

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B

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    Watching a 3D movie can more than double the concentration powers and cognitive(认知) processing of children, a new research claims.

    A study made by visual technology firm RealD and led by child psychologist Dr. Richard Woolfson suggests that children aged between 7 and 14 experienced twice the cognitive processing speed and performed better in testing after watching 20 minutes of a 3D film. This is despite suggestions that attention spans(时期) in children have shortened in the last decade due to unlimited to access to entertainment, including on-demand TV, gaming and social media. A 2015 study claimed that watching 3D content had a similar effect to brain-training exercises.

    Consumer psychologist Mr. Fagan said that the increased stimulation(刺激) found in watching something in 3D "exercised" the brain and improved performance in the short term. "3D films can play the role of ‘brain-training' games and help to make children ‘smarter' in the short term," he said. "The shortening of response times after watching 3D was almost three times as big as that gained from watching 2D; in other words, 3D helps children process aspects of their environment more quickly. This is likely to be because 3D is a mentally stimulating experience which ‘gets the brain's juices flowing'."

    The experiment saw children given a range of cognitive tests before watching 20 minutes of a movie in either 2D or 3D and being tested again. The results showed those who saw the 3D content reacted faster and performed bettering the second round of testing. Mental engagement also rose by 13% among 3D watchers. Child psychologist Dr. Woolfson added that “supportive parenting” and regularly listening to classical music can also aid a child's memory.