每台无绝缘移频自动闭塞机柜可放置（）套轨道电路设备。
A.10
B.5
C.20
参考答案：A
在劳动争议的处理程序中必须坚持先行（）。（2011年5月二级真题）
A.协商
B.调解
C.仲裁
D.诉讼
请根据下面提示，写一篇短文，词数不少于50.
In your spoken Endlish class, your teacher shows you the following picture. You are asked to describe the picture and explain how you understand it.
