When doing scientific research ,the sources used should be ?

The sources used in the scientific research purpose should be reliable.

Explanation:

In doing the scientific research, the sources must not be of popular kind but should be representative kind which could represent the material and method adopted in the research very well. The sources are never termed as new or old sources, as the source is not bounded by time but space.

The source applicability is defined by the parameter used in the specified location and not time. Therefore, the source must be reliable which could give definite information and trustworthy.

here are some information of the future of geothermal energy:

-the future of geothermal energy can pretty much be summed up with a single word: more

-scientists plan in going deeper than 120 meters

-we are hoping that one day, we will get all of our energy from renewable energy sources such as geothermal energy

hope this !