Jessica and Dana are roommates. One night while Jessica was at work, Dana was hungry, and although there was some leftover pasta in the fridge, she ate Jessica's last frozen meal instead. Dana reasoned that Jessica owed her one, because Dana had done Jessica a favor by picking up things for her at the grocery store, even though Jessica had given Dana money to pay for the things. When Jessica got home, she went to the fridge to warm up her frozen dinner. When she saw that it was gone, she was very angry, and accused Dana of eating food that wasn't hers. Dana, for her part, got angry in return and thought to herself that Jessica was just a stingy person who didn't like to share. Despite the fact that Dana was angry, she did not yell at Jessica but instead apologized and offered to drive to the store right then and there and buy another frozen meal. Jessica agreed that Dana should do that, so Dana did drive to the store and returned with a frozen meal.

answer; collective security;

me no say

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals