Answer:
1) fair use
2) register
Explanation:
It will not be fair if you copy somebodies work without citing his/her name in your work. You cannot just do that, and this is confirmed by copyright law fair use. Hence fair use completes the above sentence.
Also, the owner of the work must register his work at copyright office for getting the copyright protection.
I think the two tasks that would be completed by an emergency and relief worker are CLEAN AND STERILIZE EQUIPMENT AND MACHINERY TO USE WITH PATIENTS.
They need to be sure that the equipment and machinery they are using are clean and free from any infection causing bacteria. This is to ensure that the patients they will take care of will not suffer from infection or any further injury caused by unclean and unsterilized equipment.
Thermal Energy I think would be the answer