The 53 member states of the Commission on Narcotic Drugs, the UN body charged with supervising the application of the international drug control treaties that form the legal backbone of global drug prohibition, is set to meet in Vienna on December 2-4, and it will take up the question of making some modest scheduling changes to the way cannabis is classified。12月2-4日维也纳联合国麻醉品委员会召开会议投票？这个时间对吗？是决定意义的那个大会吗？