?????? ??????????????????? ?? ??????? ???????? ??? ???????????? ???? ???? ????? ?????? ????????? ?????? ?~??- ?? ???? - ???? ???? - ?? - ?????- ???? - ???? - ?? ?????- ?????? ???? ???????????????????????????? ??????.If a grammatical principle that may be additional to ????is often a vowel ??and there's no other option in addition to a vowel ??then