Answer:
Africans passed down their history orally instead of writing it down.
Explanation:
Many African tribes never developed a system of writing on their own, so it was passed down orally.
Answer:
वायुमण्डल में एक निश्चित मात्रा में पाई जाने वाली गैसों- नाइट्रोजन, ऑक्सीजन तथा कार्बन-डाई-ऑक्साइड की मात्रा क्रमशः 78 प्रतिशत, 21 प्रतिशत और 0.3 प्रतिशत है और शेष असक्रिय गैसें पाई जाती हैं।
The hotter it’s temperature is
If the mixing stopped, the temperature on the surface zone would change a lot faster, which mean the water surface will evaporate faster in hot temperature and it cold down faster in cold temperature ( which could make the ocean surface freezed during winter)
