基础制动衬套，制动圆销材质，硬度有何要求？

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装用转8AG、转8G、转K1、转K2、转K3、转K4型转向架车辆的各制动衬套材质为奥-贝球铁，硬度为38～48HRC；制动圆销材质为45号钢，热处理后表面硬度为50～55HRC。控制型转向架车辆的各制动衬套材质为27SiMn，硬度为45～59HRC；制动圆销须采用材质为45号钢的外球套和奥-贝球铁的内球套。

完形填空

Tong Shiqiang rushed into a kindergarten behind his primary school several times, carrying a __36__ of kids each time he rushed out of their classroom on that fateful（灾难的）day. Only 14 years old and 1.5m tall, Tong can now __37__ a national bravery award for saving seven children.
The grade-6 student was __38__ a Chinese language class in Zhongwang Primary School in Qishan village of Longnan city, one of the worst-hit areas in Gansu province, __39__ the deadly quake struck on May 12,2008. There were 49 __40__ students in his class at the time.
"Windows began rattling(嘎嘎响）and it __41__ as if lots of bees were singing underground," __42__ Tong Shuangxi, Tong Shiqiang’s teacher and uncle. "The sound grew __43__ ... and then I __44__ it was an earthquake."
The teacher cried: " __45__ out!" All the students ran out of the room immediately.
__46__ outside, Tong Shuangxi rushed toward the kindergarten where the children __47__ a nap (午睡). Tong Shiqiang ran with him.
Only three of the kids had __48__ to run out of their room when they __49__ the building. The rest were crying, too __50__ to move. It __51__ less than three minutes for them to carry out all the five- and six-year-olds to __52__.
__53__ whether all the kids had been saved, Tong and his nephew had __54__ begun checking the name list when the classroom’s walls fell down. "That’s the only time I was scared," said Tong Shiqiang.
The 14-year-old is __55__ to be nominated (提名) for the child hero award, to be given by the Ministry of Education and the Central Committee of the Chinese Communist Youth League.

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[文字开始] 万维网(World Wide Web，简称Web) 的普及促使人们思考教育事业的前景，尤其是在能够充分利用Web的条件下计算机科学教育的前景。有很多把Web有效地应用于教育的例子，但也有很多误解和误用。例如，有人认为只要在Web上发布信息让用户通过Internet访问就万事大吉了，这种简单的想法具有严重缺陷。有人说，Web技术将会取代教师，从而导致传统教育机构的消失。 [文字结束]

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