题干

某同学做“唾液淀粉酶的消化作用”实验记录如表,结论错误的是(  )

试管

加入物质

温度

时间

碘液检测

1

淀粉糊+唾液

37℃

10分钟

不变蓝

2

淀粉糊+胃液

37℃

10分钟

变蓝

3

淀粉糊+唾液

0℃

10分钟

变蓝

A:对比1和3,得出唾液在适宜温度下对淀粉有消化作用

B:对比1和2,得出胃液对淀粉无消化作用

C:对比2和3,有两个变量,不能得出科学结论

D:分析1试管,可得出唾液能将淀粉分解成麦芽糖

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答案(点此获取答案解析)

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.