问题 问答题 简答题

乙炔发生器的构造和使用上应符合哪些要求?

答案

参考答案:(1)发生器的生产效率必须与气焊、气割时乞体需用量相适应;

(2)发生器的发气效率必须达到80--90%;

(3)发生器电石分解过程应能够根据气体需用量而自自动调节;

(4)乙炔压力稳定、纯度高;

(5)乙炔温度低。发生器电石分解处温度不得超过100--170℃,气体输出处乙炔温度不得高出环境温度10--15℃;

(6)乙炔发生器必须装有安全装置,保证乙炔过量时能够排除;

(7)构造要简单,使操作方式便;

(8)移动式乙炔发生器必须体积小、重量轻、移动方便。

写作题

书面表达。

     A man stabbed eight school children to death and injured five others while they were waiting at their

school's gate in Nanping City, Fujian Province, on the morning or March 23. On the evening of December 7,

2009 a stampede (蜂拥挤迫) in private Yucai Middle School in Xiangxiang City, central China's Hunan

Province, killed eight students and injured 26 others.

     阅读上面短文,然后根据要求用英语给《广州英文早报》写一篇短文,谈学校安全问题。

要点如下:        

     1、 全社会都要注意学校安全问题,避免悲剧再次发生。

     2、 学校要进行安全教育。教育学生上下楼梯要排队,小心拥挤;在上学路上骑自行车要慢速,

            横过公路和街道时要确保安全才通过。

     3、上课时间学校要关闭大门,禁止陌生人进入校内。

     4、学校确保学生吃上质量好的肉和没受过污染的青菜。

     5、希望学校安全状况会越来越好。

写作要求: 

     1、 句子结构准确,信息内容完整,可适当发挥,篇章结构连贯。

     2、 文章开头已为你写好。

     3、 全文应该有100个单词左右,不包括给出部分。

参考词汇:学校安全:school safety    上下楼梯:go upstairs and downstairs

      It is reported that a number of students lost their lives or were injured in the accidents which happened

in the school campuses. As a student, here I'd like to say something about this.                                          

                                                                                                                                                         

                                                                                                                                                         

                                                                                                                                                         

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