AC signal的用法和样例：
例句
- A continuity tester injects an AC signal into the conductors of a cable to find circuit faults.
一个连续性测试器给电缆导线注入交流信号，从而找到电路故障。 - With the information and the undistorted parts, the whole spectrum can be recovered by solving the nonlinear equations, so the AC signal is also recovered.
这一先验知识结合信号中未失真的频谱部分，通过求解一组非线性方程即可近似恢复出交流信号的全部频谱，从而恢复出完整的交流信号。
