slowly varying amplitude approximation

例句：

1. 1. The slow-moving car was a challenge for the driver to keep up with.
   这辆慢速行驶的汽车对司机来说是个挑战，要跟上它。
2. 2. The scientist used a slowly varying amplitude method to study the behavior of the system.
   科学家使用一种缓慢变化的振幅方法来研究系统的动态行为。
3. 3. The engineer had to make a slowly varying amplitude approximation for the complex system.
   工程师不得不为这个复杂的系统做出缓慢变化的振幅近似。