Name the major river sytems of north america

the Missouri River

ne pare rău, dar când mi-am căutat întrebarea, doar avioanele au apărut .. deci, ar putea fi răspunsul, sau ar putea fi baloane cu aer cald, deoarece acestea pot conta și ca ambarcațiunile de aer, dar nu sunt complet sigur de asta. a fost doar o presupunere, sper că am ajutat, îmi pare rău dacă nu am făcut-o. de asemenea, folosesc traducerea google, pentru a traduce ceea ce spun în engleză, așa că îmi pare rău dacă gramatica sau chiar limba nu este corectă

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