Explanation:
Radio Waves -- The waves in the electromagnetic spectrum that have the longest wavelengths and lowest frequency are called radio waves.
Standing water is not good for the environment so it needs to be vanished and shall no longer be around humans or animals that can catch the deadly disease malaria !
Answer:
Example: If you want to explore the effect of salt on a plant growth, the control group would be a set of plants not exposed to salt, while the experimental group would recive the salt treament, so you answer is control group.
The adjective is 'difficult' since it is describing the maze.
