***** NOT A TEACHER *****
Hello, Hitinvo.
(1) I agree with crazYgeek.
(2) "carry on" = to continue.
(a) "carry" (verb) + on (adverb particle) = phrasal verb.
(3) "underground" in this sentence is an adverb.
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(a) That building has an underground parking garage. (adjective)
(b) During the war, she worked with the underground. (noun)
***** Thank you for the question *****