题干

下列说法正确的是(   )

A:“明天降雨的概率是80%”表示明天有80%的时间都在降雨

B:“抛一枚硬币正面朝上的概率为 12 ”表示每抛2次就有一次正面朝上

C:“彩票中奖的概率为1%”表示买100张彩票肯定会中奖

D:“抛一枚正方体骰子,朝上的点数为2的概率为 16 ”表示随着抛掷次数的增加,“抛出朝上的点数为2”这一事件发生的频率稳定在 16 附近

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D

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    Schools across the world are trying to come up with solutions to keep students active. Some are replacing traditional classroom chairs with exercise balls or standing desks. At Ward Elementary School in Winston, North Carolina students have adopted a new program that requires riding fixed bikes while reading.

    'Read and Ride' is the creation of school counselor Scott Ertl, who came up with the idea while he was exercising and reading at the gym. Believing it would be a fun way to convince students to become more active, he placed one in the corner of his classroom and encouraged them to use it during independent reading classes.

    It was so popular that Ertl decided to add more bikes and offer the Read and Ride program to the entire school. Today Ward Elementary has a dedicated exercise room filled with bikes that can be used by students while completing their daily reading assignments.

    Besides making reading more fun, the program also helps students exercise at a comfortable pace without the pressure that comes with regular sports-related activities. It is also a perfect way to release energy during days when the weather is not helpful to outdoor activities.

    Most importantly, however, are the program's academic benefits. A year after Read and Ride was introduced at Ward Elementary School, students actively involved in the program demonstrated an astonishing 83% reading proficiency. Those that had not taken advantage of the exercise bikes tested at a much lower, 41%.

    Though the substantial improvement in academic achievement cannot all be attributed to programs like Read and Ride, experts believe they are a significant contributor. That's because studies have shown that physical activity stimulates(刺激) brain cells and helps prepare it for learning. As word of the difference made by this easy to execute exercise program spreads, don't be surprised to find schools across the country adopt “Read and Ride” for their students.