Redback
n. 赤背蜘蛛；力博通信公司
🗣️ 情景例句
Where's Mom?
妈妈呢？
I hope you agree with me.
我希望你同意我。
and a period (which is the time it takes a wave crest to travel one wave length).
和周期（浪峰走过一个波长所需的时间）。