What is the column of rock in the mantle

Which of the following is not a place where hydrogen can be found on earth? a. natural gas well b. atmosphere c. water d. mine

Which of the following east asian contries are a peninsula? a. china b. taiwan c. south korea d. mongolia

Which ecosystem best fits the characteristics listed below? which ecosystem best fits the characteristics listed below? ii. seasonal migrations of millions of wildebeests, zebras, and elephants iii. large numbers of predators, such as lions iv. acacia trees and grasses a. the congo rainforest b. the african mangroves c. the serengeti grasslands d. the sahel