焊条R317牌号是( )焊条。A．碳钢 B．结构钢 C．奥氏体不锈_爱下问搜题

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问题单项选择题

焊条R317牌号是( )焊条。

A．碳钢

B．结构钢

C．奥氏体不锈钢

D．珠光体耐热钢

答案

参考答案：D

补全对话，情景问答

选择正确的句子组成对话。

( ) 1. What day is it?
( ) 2. Yes! It's sunny.
( ) 3. It's 7: 00.

A. What time is it?
B. Is it sunny?
C. Sunday, July eleventh.

问答题简答题

城市社会流动的影响有？