The 17th of Tammuz--this week on Thursday—is the dawn-to-nightfall fast day (see article #3) commemorating the breaching of the walls of Jerusalem. It starts the Three Weeks of semi-mourning (see article #4) culminating in Tisha b'Av (9th of Av) the anniversary of the destruction of the Holy Temple.
The 2nd article is for the sixth chapter of Pirkei Avot, completing the 2nd cycle for those who study it on Shabbat afternoons throughout the summer.
Articles 4,5,7 are for the weekly reading, Pinchas.