(Bishul Ep. 71) (#84) Could one return food to the blech if one is missing 1 or 2 conditions?

Folding Garments on Shabbos, קיפול בגדים (Kipul Begadim). How הכנה (Hachana) Has to Do With Folding Garments on Shabbos;

Playing Basketball or Soccer Outside and Rolling Items on a Covered Ground (e.g., on a Carpet, Mat, Board, etc.);

Does It Have to Be Done for Immediate Use? How Should One Make Salt Water on Shabbos and Yom Tov for the Seder on...