There isn't any one answer to this question, as it's asking you to create a mnemonic device to help you remember the names of these types of energies. In case you are confused on what a mnemonic device is, it is a phrase/acronym used to help you remember words with the same first letters of each word in the acronym. Examples:
"Never Eat Soggy Waffles" for "North, East, South, West"
"King Henry Died by drinking chocolate milk" for the metric prefixed "Kilo, Hecto, Deka, base unit, deci, centi, milli".
So, to answer your question, you should come up with a phrase that will help you remember those words. The phrase should have six words with one beginning with each of these letters "N, C, R, E, M, T" in any order.
To give you an example of one I just made up, you could say "Never (Nuclear) Create (Chemical) Metals (Mechanical) That (Thermal) React (Radiant) Excessively (Electrical)".
