电焊机一次电缆一般不超过（）米。
A.2～3
B.3～4
C.4～5
参考答案：A
The train arrived and they were just to catch it. [ ]
A. on time; on time
B. on time; in time
C. in time; in time
D. in time; on time
【问题2】 在图2-7所示的配置文件中，第14行至第18行实现什么配置功能
