La Carta for Dummies
频率是单位时间内完成振动的次数，是描述振动物体往复运动频繁程度的量，为了纪念德国物理学家赫兹的贡献，人们把频率的单位命名为赫兹，简称“赫”。The corporate just released an up to date Variation previous 7 days, And it will be used in around 50 undergraduate and graduate classrooms
频率是单位时间内完成振动的次数，是描述振动物体往复运动频繁程度的量，为了纪念德国物理学家赫兹的贡献，人们把频率的单位命名为赫兹，简称“赫”。The corporate just released an up to date Variation previous 7 days, And it will be used in around 50 undergraduate and graduate classrooms