标签：ha=m

2020-02-17到2020-07-16

标准件及常用件 标准件及常用件单元测验

1、 公称直径为24mm，中径、顶径公差带代号均为6g的普通粗牙螺纹表示为(　　　)。

A:M24
B:M24×2-6g
C:M24-6g
D:M24×2LH-6g
答案: M24-6g

2、 绘制内螺纹时，螺纹的牙底（大径）用（ ）表示。

A:粗实线
B:细实线
C:细点画线
D:细虚线
答案: 细实线

3、 连接两个不太厚的零件和需要经常拆卸的场合一般采用（ ）。

A:螺

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Unit 1 What do you know about China？ — Geography & History Unit 1 Test

1、 With which event is Chinese history divided into two main periods?

答案: The Opium War of 1840.

2、 What changes did the Opium War bring to China?

答案: China opened its door to the world during and after the war. 

3、 Which one is the 3rd longest river in the world?

答案: The Yangtze River

4、 Which one is universally recognize

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