How did Isaac Singer contribte?

How many pounds of coffee beans selling for 2.00 per pound should be mixed with 3 pounds of coffee beans selling for 1.20 per pound to obtain a mixture selling for 1.76 per pound? What biome might be in if were standing on a bitterly cold dry plain with only a few short plants scattered around? Early organisms in the Precambrian era converted to oxygen.? What caused the failure of her fort Laramie treaty that promised to protect native Americans lands as long as the grass shall grow? How many sides does a triangle? List and explain the 3 steps that cells use to make protein? Who agrees on the native American argument against the English settlers? Why do some people look like fish? What happen to the ship in The Cay? What is the saying of New Jersey? Ferrari 360 front or rear wheel drive? I am a Phoenician princess abducted to Crete by Zeus who had assumed the form of a white bull and by him the mother of Minos What moon are you? How do hyenas avoid or heat? What branch of mathematics is concerned with sines and cosines? Is rice a chemical? Can you get a tax return for daycare payments Not head of household? What movie and television projects has Silvia Claes been in? What crimes are elderly people subjected to? Is waist an example of pivot joint? What is the word for spanish miss?

How did Isaac Singer contribte?