Activity $5\mathrm{.}1\mathrm{.}1.$ What is the constitutional basis of the right to collective bargaining? in philippines

Activity $5\mathrm{.}1\mathrm{.}2.$ What are the conditions precedent prior to collective bargaining?

Activity $5\mathrm{.}1\mathrm{.}3.$ When is there a duty to bargain?

Activity $5\mathrm{.}1\mathrm{.}4.$ What are the key contents of a CBA?