Answer:
a phrase does not have a noun or a verb, while a clause has a noun and a verb
C.Swimming is my favorite form of exercise; it gives me energy.
So in a semester, before the week starts, I usually organize my lessons and the expected lessons for the new week. I start to look for techniques that is suitable for me in studying and that can easily make me learn and remember my lessons. One of the study tools I use is having a separate note pad which I used to summarize my lessons. Hope this answer helps.
Generally, swing dance is used only as a noun not a verb. Therefore, the past tense would just be "swing dance." However, if you used it as a verb, you would probably use the past tense of dance, so it would be swing danced.