understanding the concept of "אין צובע באוכלין" (no coloring by food that's eaten)
(Squeezing materials.) introduction to the halachas of a "SPONGE";
different types of bags on rolls, small packets of sugar, ketchup, etc.; bags that will never completely open;
(Squeezing materials.) the correct procedure in reference to wiping up spills on a counter, table or floor with a towel or rag;