Ultrasound refers to a sound wave with a frequency greater than the upper limit of human hearing, which is generally over 20 kHz. In general, humans can hear sounds with a frequency between 20 Hz and 20 kHz.
Pastoral Herding is also known as nomadic herding and pastoral nomadism. This is an economic activity more advanced than food gathering and hunting because the people living by pastoral herding make at least some investment to enhance natural production. Labour to enhance and nurture the supply of animal products is the chief investment of the peopleengaged in this occupation.
EXAMIANS