What is the significance of the placement of the haftara of Shabbat Shuva and "Dirshu Hashem" in the wake of the Sheva Denechemta? What type of teshuva is referred to in the haftara "Shuva Yisrael"? Is it different from the type of teshuva discussed in "Dirshu Hashem"? What do the verses from Yoel add to the verses in Hosea?