higher in summer than in winter. Regional differences and day and night differences in the metals and water-soluble ions commonly existed. The PMF analysis indicated that coal combustion and transportation-related sources were the predominant sources in the urban and suburban areas in the daytime in winter, and secondary aerosols were the most important source for the suburban area in the nighttime in winter. There were more pollution sources of PM2.5 during the daytime in summer, especially in the suburban area. In the nighttime in summer, the pollution sources of PM2.5 in the urban and suburbs areas were basically the same, but the source apportionment was quite different.same support that federal judges in Mississippi, Tennessee, Alabama, and Maryland have all ruled in varying forms over the last 30 years to be unconstitutional. And while Obama had every opportunity to address these issues not as racial problems, but as economic and social justice issues impacting all Americans, he chose at every turn to double down on his disdain for HBCUs.

He told Morehouse graduates to be better fathers and to stop being cynical. He tried to create a national ranking system for colleges to expose institutions with bad metrics. He proposed that everyone go to community college for free. He told the CBC to tell HBCUs to stop complaining and get their graduation rates up. He never attended one HBCU National Conference. He told a Southern University