We can use another form of variable expansion to select a specific substring, based on a specific character offset and length. Try typing in the following lines under bash.
可以根据特定字符偏移和长度，使用另一种形式的变量扩展，来选择特定子字符串。
2
With others, like the variable-speed chilling devices and lighting, there was an offset to be considered in the immediate investment of capital.
其他一些，像变速的冷却设备及照明等，则可弥补未考虑进直接基建投资的不足。
3
LCL_NUM_VALUE is the offset from the end of the stack to the local variable num.