Which of the following can be reduced by the use of renewable energy sources

Social cost, Economic costs and Environmental Costs could be reduced by using Renewable energy sources like Hydro Power, Solar Power, Wind Power, Biomass and Geothermal plants.  They can provide sustainable energy services since they are available all of the time. They known to have less impacts on various aspects especially in the environmental aspect comparing it to nonrenewable resources like fossil fuel based power plants.  

You can still be friends with each other. you don't have to date since he likes someone else. just stick to being friends for now

It shows that the experiment is designed properly.