问题 单项选择题

天然气气门站位于二级地区,站内管道设计压力为4MPa,管径为DN500,钢管采用L290管道钢,管壁厚度和弯头(R=2D)壁厚度为()(F=0.5,DN500外径D=508mm)。

A.7.1 mm,9.0 mm

B.7.1 mm,8.7 mm

C.7.5 mm,9.0 mm

D.7.5 mm,8.7 mm

答案

参考答案:B

解析:

弯头壁厚δ’=7.1×1.17 mm=8.3 mm取8.7 mm

补全对话,情景问答
[ ]

A. My name is Jenny.

B. Hello! What's your name?

C. I'm Jenny.

2. 当你与Jenny道别时,你应说:[ ]

A. Good morning, Jenny.

B. Good-bye.

C. Hello!

3. 当你想知道李明在哪儿时,你会问:[ ]

A. How is Li Ming?

B. Where is Li Ming?

C. What is Li Ming?

4. 当有人对你说“How are you?”时,你应回答:[ ]

A. Good.

B. Fine.

C. Chair.

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单项选择题