Why do you think PCMS cool down after a while​

.In order to avoid insufficient discharge of the PCM and in general to avoid the stored thermal energy being released back into the conditioned space, a system where PCM is arranged along the façade with direct contact to the inside and the outside is a possible solution.

Explanation:

A phase change material absorbs and releases thermal energy in order to maintain a regulated temperature. ... The PCM, now in its liquid phase, can release the heat it absorbed as the external temperature decreases. During this time period, the PCM solidifies and provides a warming effect.

i think the answer is the one about environmental and social health.

hope this

b europeans take corn to africa. corn becomes an important crop there.