???? ??? ????? ?????? ?????? ?????? ???? ??? ??????. ???/??/??? ????? ?????? ????? ???????, ? ??? ????? ???????/demand and supply ??? ????? ??????/????. ????? ??? ??????? ?????/???????/?????? /???? ????? ?/among ??????????/???????/???????. ????? /???? /??? ??????? ??????? ?????? /????????? ??/????? ????????? ?? ?????/???????? ?? ?????/invest