学校多功能教室的地板是用瓷砖铺设的，瓷砖的包装箱上标有“瓷砖_爱下问搜题

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问题问答题

学校多功能教室的地板是用瓷砖铺设的，瓷砖的包装箱上标有“瓷砖的最大承受压强是6×10⁶pa”质量是为300Kg，着地面积为3×10^-5m²的电器设备．g取10N/kg．试问：

（1）电器设备是否可以直接放置在教室地板上？通过计算说明理由．

（2）应采取什么措施安装电器设备才不会损坏地板？说出理由．

答案

已知：m=300kg，S=3×10^-5m²，p_最大=6×10⁶Pa，g=10N/kg

求：（1）判断电器设备是否可以直接放置在教室地板上；

（2）采取安装电器设备的措施．

（1）电器设备对教室瓷砖的压力：

F=G=mg=300kg×10N/kg=3000N，

电器设备对教室瓷砖的压强：

p=

F

S

=

3000N

3×10-5m2

=10⁸Pa，

∵p＞p_最大，

∴电器设备不能直接放置在教室地板上；

（2）∵在压力一定时，增大受力面积可以减小压强，

∴可以采取增大受力面积即增大电器的着地面积来安装设备．

答：（1）电器设备不能直接放置在教室地板上；

（2）应加大电器的着地面积，以增大受力面积，减小压强．

完形填空

The young boy and his father sat quietly watching the snow fall on a snowy Saturday afternoon.
“Dad, my friend told me that every snowflake is 36   . But they look all the same to me. How can we tell?” the child asked.
Dad felt it was his 37 to give a more satisfying answer. “Son, snowflakes are like people. We are each   38 in a very special way. We can test it right now,” he said.
The child stood up, put out his hands, and 39 as snowflakes landed on his gloves. “These snowflakes are all different on my gloves, but those in the yard look the same. Together they are even more_ 40 and striking. Then if people are like snowflakes, why don't they    41 ?”
“Choice,”Dad said. "Their choices 42 them what they are.”
“ 43 choice is a bad thing?” the boy asked.
“Oh, no. Only when we choose the 44 things.”
“How do we tell right from wrong?" the child asked.
Dad was given the chance to build upon the foundation of his son's 45 . He reached down and began to 46 with the snow. He 47 the snow into two sides, three large snowballs on one side and several smaller ones on the other.
“Which side did the right thing?” he asked the boy.
The child looked at both sides but 48   answer. Then Dad placed the three larger snowballs on top of each other.
“It’ s a snowman! The side 49 made me snowman!” the boy replied with 50
Yes, all these people came together and recognized how special each of them was, so they joined in a(n) 51   to build up mankind,” Dad said.
The child then stood up and 52 an arm full of the smaller snowballs. One by one he began to throw them at the other small piles of snow. He said,”This is what happens when people can't work together. They have a(n) 53 .”
Dad was shocked. He stood up, lifted the boy and 54 him tightly, whispering to him, “I hope that your world will learn to work and live together. I hope you will make the right   55
and learn to build the best snowman ever.”

C．responsibility

C．comfortable

D．significant

A．communicate

C．distinguished

A．disappointment

B．frustration

C．organization

D．negotiation

单项选择题

缔约过失责任的特征不包括（）。

A.缔约过失责任是在订立合同的过程中产生的责任

B.缔约过失责任是一方当事人违反依据诚实信用原则所产生的义务的责任

C.缔约过失责任是对信赖利益造成损失的赔偿责任

D.缔约过失责任是一方当事人违反依据全面履行原则所产生的义务的责任