Before computers how did map makers create map projections

Plants can have a positive and negative effect on the rate of weathering

How did the korean war impact the elections of 1952?

Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes. b. it burns more cleanly than crude oil products. c. scientists have developed new ways of extracting it. d. during its extraction, groundwater can be contaminated.