Montreal Protocol (1973) and the international agreement signed (1985 & 1987). The treaty is structured around several groups of halogenated hydrocarbons that deplete stratospheric ozone. All of the ozone depleting substances controlled by the Montreal Protocol contain either chlorine or bromine (substances containing only fluorine do not harm the ozone layer). Some ozone-depleting substances (ODSs) are not yet controlled by the Montreal Protocol, including nitrous oxide (N2O) For a table of ozone-depleting substances controlled by the Montreal Protocol see: For each group of ODSs, the treaty provides a timetable on which the production of those substances must be shot out and eventually
Full-service community schools in the United States magnet schools, and alternative schools, the full-service community school model is one of many educational reform efforts that are intended to increase student achievement, but the full-service community school model specifically focuses on the development of the community as a whole. A charter school receives public funds but is not subject to all of the rules, regulations, and statutes public schools must adhere to. A charter school is accountable to what is sent forth in its individual charter. A school voucher is a certificate issued by the government to allow families to apply it the cover the tuition at a