A) what two processes account for adding free oxygen to the precambrian atmosphere? b) what do we mean by free oxygen, and c) which of these two processes were most important?

Explain the cause for movement river valley civilization to early industrial centers

Which statement about factories in the industrial revolution is not true? a) some of the first advances were in textile mills b) spinning machines used water power c) water power was replaced by steam power d) coal was imported to english factories for power answer d) coal was imported to english factories for power

If we review the changes in the landscape surrounding the great salt lake in utah we can see a change in topography. look at the area to the south of the lake. what change has occurred during the last twenty-nine years? a) erosion of the hills b) an increase in marshland c) flooding of the area and the development of wetlands d) deposition of sediments and an increase in elevation