2. Importance of root and tuber crops in Africa. In Africa, roots and tubers are generally grown in countries located in the Sub-Saharan zones, notably in Nigeria, Ghana, Cote cÃ´te'D, Ivoire, Nigeria, Benin, Cameroon Central African, Republic.D.R, C, Tanzania, Mozambique, Angola, Uganda, Malawi madagascar And. rwanda
The healthy human ear can hear frequencies ranging from 20Hz to 20,000 Hz. Over time, the hair cellâs hair-like stereocilia may get damaged or broken. If enough of them are damaged, hearing loss results. The high frequency area of the cochlea is often damaged by loud sound.
Humans can hear sounds approximately within the frequencies of 20 Hz and 20,000 Hz. Anything below 20 Hz, typically cannot be heard although it can be felt. This can be experienced to when you feel the bass of a song. Likewise humans normally cannot hear any sounds above the frequency of 20,000 Hz.