first harmonic

first harmonic

基波, 一次谐波

例句与用法：

I learned about the incident at first hand because I know one of the policemen who worked on the case.

我直接获悉了该事件的情况，因为我认识调查这个案子的其中一个警察。

I found out my grades on the internet at first hand.

我从网络上直接得知我的成绩。

I had experience at first hand of the worst aspects of that banking system.

对那套银行系统中最糟糕的一些问题，我有过亲身体验。

It is much cheaper to buy goods delivered at first hand.

买第一手货会比较便宜。