Which of the following elements produces no harmful emissions when used as an energy source? a. coal b. oil c. wind d. natural gas

What was the most difficult obstacle to overcome in the creation of an autonomous state after indian independence was achieved? a british willingness to go to war to retain the region b. religious differences between hindus and muslims c. ethnic differences between tribal regions d. indian princes' inability to decide on a format of government

What's erosion? a. the breakdown of rock into smaller pieces b. the removal of weathered products from rock c. a change in rock resulting from exposure to water d. a chemical change in rock that weakens it

In the following diagram, four different index fossils are labeled: which of the labeled fossils comes from the oldest organism? a b c d