Opening introduction to the concept and special opportunity of chol hamoed in contrast to yomtov and the weekday, Rabbinic permission to engage in activities to avoid financial loss to encourage simchat yomtov.
The special maftir and haftara readings of Shekalim, Zachor, Parah and Hachodesh- what happens when there is a clash of two possible haftarot- Rosh Chodesh on Shabbat during the 7 weeks of comfort following 9 Av?