Hi the answer is yes , time flies when you are having fun is a metaphor.
You can find the key to pronunciation marks in a standard dictionary in an appendix.
(of electromagnetic radiation) having a wavelength just greater than that of the red end of the visible light spectrum but less than that of microwaves. Infrared radiation has a wavelength from about 800 nm to 1 mm, and is emitted particularly by heated objects.
Conjunctions combine two sentence fragments or sentences to become a complex sentence.
