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.
MOST OF THE TIME, it's in an animal's best interest to be undetectable, but sometimes it's useful to be loud-very loud. While a normal human conversation registers at about 60 decibels (dB), some animals can screech, scream and holler much louder than a subway train (100dB). The human threshold of pain is 120, and at 160 your eardrum will rupture, but many loud animal calls are not designed for human ears.