The most convincing explanation is that when someone is finding it difficult to understand what is said to them, he/she engages in a form of lip-reading: he/she will observe the lips of the talker and mimic the talker's lip movements.
Lake Tanganyika is an African Great Lake. It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, in both cases, after only Lake Baikal in Siberia; it is also the world's longest freshwater lake.
Lake Kariba: LakeKariba is a hydroelectric lake which is situated in between Zambia and Zimbabwe. It is one of the most beautiful and largest lakes in the world. It is expanded in an area of 180 cubic kilometers and contains tons of water with about 55oo square kilometers surface area.