H2O or water, all humans are mostly mad of water and water covers most of the earth
Answer:
D.
Explanation:
Water is polar, for one thing. Polar mixes with polar, nonpolar mixes wih nonpolar. This leaves D.
Frequency is represented by f in the formula v=fπ. Where π is wavelength , f is frequency and v is velocity. Frequency is the number of waves passing per unit time.