Understanding the type of knots that are allowed to be opened on Shabbos.
The Difference Between Trapping a Bee and Trapping a Fly;
to clog a small crack in a pipe. Turning off gas range. Putting on, taking off smoke detector. Unscrewing the bulb that's off;
Dried-out Trees, Fruits, Branches, Alfalfa and Bean Sprouts. Putting an Aravah into Water;