水的比热容较大,生活中,我们常用水来加热或散热,例如:冬天常用热水袋取暖,把质量

题型:填空题

问题:

水的比热容较大,生活中,我们常用水来加热或散热,例如:冬天常用热水袋取暖,把质量为2Kg,温度为90℃的热水装入热水袋中,到温度降为30℃的时侯,此水放出了___________J的热量;如果用相同质量,相同温度的沙来取暖,这沙会冷得_______ (填“快些”或“慢些”)。【C=4.2×103J/(kg·℃)】

考点:热量的计算
题型:填空题

阅读理解。

     People travel to work in different ways. Some people go to work on foot because they live near their

work places. Some people go to work by bike because they live farther away, or they like riding bikes.

They think it's good for their health. Today more people have private (私人的) cars, so they can go to

work in their cars. In the south of China, many people even go to work by boat because water is around

their houses. Will people go to work by plane? I think so, if necessary (如果必要的话).

( )1. All people like to go work by bike.

( )2. Some people think it's good to go to work by bike.

( )3. Today more people drive to work.

( )4. In the north of China, many people go to work by boat.

( )5. The writer thinks some people will go to work by plane if necessary.

题型:填空题

在四边形ABCD中,∠D=80º,∠A,∠B,∠C的度数之比为3:5:6,则最大的内角是_______度.

题型:填空题

超硬石膏粉水比例约为()

A.100g:25ml 

B.100g:35ml 

C.100g:45ml 

D.100g:55ml 

E.100g:16ml

题型:填空题

同种元素的不同微粒,它们的(    )

A.电子层数相同

B.质子数不一定相同

C.相对原子质量一定相同

D.化学性质一定相同

题型:填空题

0.1313是纯循环小数.______.

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