?????????? ???? ?????????? ??????? ?? ???? ?????? ??????Because the saying goes: "Jack of all trades, learn of none, however ofttimes better than learn of 1." But principals are not able to pay for to be master of none???????? ??? ?????????? ???????  ??? ?? ?????? ???????? ??? ????????? ???? ?????? ??? ???????? ?? ?????? ??? ?????? ?? ???????????