Explain the difference between cross sectional studies and longitudinal studies and provide an example for each.

The subject option isn't available. the topic is earth science!suppose you are a city engineer whose job it is to explore how to use more renewable energy in your locality. 1. consider the resources in your city and select one of the following: - hydropower -solar power -wind power -geothermal power 2. prepare a pamphlet or multimedia presentation to convince a committee of citizens and local leaders that the renewable energy source you have selected is best for you locality. in your pamphlet or presentation include: - a discussion of the renewable energy source that is best for your town and why -a discussion of the advantages and disadvantages of this energy source -a discussion of why you think your city should use more of this energy source -how the use of renewable energy will impact your city -pictures and/or charts and tables to strengthen your arguments

Which of the following situations would most likely occur if a human-induced event caused the ocean water to become the same temperature around the world? deep ocean current circulation would increase salt distribution around the world's oceans. surface ocean current circulation would distribute heat around land masses at a faster rate. new, fresher water would float on top of dense salt water and limit thermohaline circulation. some land masses in the northern hemisphere would start to warm up over time, melting snow and ice. runoff of surface freshwaters and rainfall would no longer have an effect on the salinity of ocean waters.

Which of these is a disadvantage of hydrogen fuel cells? a. engines that use hydrogen fuel are more efficient than gasoline-powered engines. b. the only emission produced by hydrogen fuel cells is water. c. hydrogen fuel is continually available and useful for heating. d. hydrogen fuel is often purified in a process that emits lots of greenhouse gases.