PLEASE HELP ASAP!! How does the friction affect the total time a pendulum is in motion? And what could cause this friction in the real world?

In the diagram below, the northern hemisphere would be in what season at position a a.fall b. winter c.summer d.spring

Based on her survey, which advertising mediums will work best to publicize leslie's in-store specials?

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.