Answer:
1) The distance between two consecuitive peaks is called the wavelenght, so:
A = wavelenght.
The middle of the wave is called the rest position, so:
D = Rest position.
The distance between a peak and trough is called the wave heigt, so:
C = Wave height.
The distance between the rest position and a peak or a trough, is called the amplitude of the wave:
B = Amplitude.
2) Usually in high frequency waves we have shorter wavelenghts and in low frequency waves whe have larger wavenelgths, this is because the relation between frequency and wavelenght comes from:
velocity = wavelength*frequency.
if the velocity is constant, and we have a increace in the frequency, the wavelenght must decrease (so the velocity remains constant).
The same happens if the frequency decreases, the wavelenght must increase.
