Answer from cs61c-em (JinHyung Park 17762465) for Question 3
I think the keyword "new", and.. there is no function like C's free.

no. there is the 'Boehm-gc' that is a gargabe collector for C and C++.

the site is http://www.hpl.hp.com/personal/Hans_Boehm/gc/
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it can be used a library, and also included in GCJ  that is GNU java native compiler for garbage collecting.