Answer:
A) They are named for the places where geologists first described rocks or fossils from that time
Explanation:
The relationship between plant and animals, layers and types of rocks, fossils and radioactive dating are used for preparing Geologic Time Scale. Geologic time is comprise of four Eons namely Hadean (the initial stage) followed by Archean and Proterozoic and Phanerozoic in the recent . The Eons are classified into eras and theses eras reflect the changes in fossil record. Eras are further divided into periods and some periods into Epochs.
In periods a single rock system is found while the division in the era's reflect major changes in fossil record.
To find a better place to live with more recourses
Answer:
Merchants brought several goods and salt in exchange for gold and other precious items like ivory, kola nuts, leather, dates and metal goods.
Explanation:
The West African Kingdoms included Ghana, Mali, and Songhai. All three kingdoms situated near the Niger River. Trade became the main source of economy. The presence of gold in the empires helped in gaining their influence in Africa, flourish in trans-Saharan trade and with Europeans. European for the first time in the 15th century, came into contact with Africa, which led to the expansion in trade and slave trade.
D found greater employment opportunities in industrial jobs
