I believe that the answer to this question is the letter A!
An object that travels around another object in space, is called a Satellite.
Answer: Gamma-rays have the smallest wavelengths and the most energy of any other wave in the electromagnetic spectrum. These waves are generated by radioactive atoms and in nuclear explosions. Gamma-rays can kill living cells, a fact which medicine uses to its advantage, using gamma-rays to kill cancerous cells.
Explanation: :)
Answer
The challenge when trying to protect the environment is expensive clean energy startup cost
Explanation
In attempts to protect the environment, energy users across the globe are shifting to new renewable energy resources which are faced by the challenge of high capital cost. Renewable energy technologies are cheap to operate but very expensive to build. The perception is that renewable energy resources are risky because they require higher construction costs.
