4. Exercise IV

The impurities are removedimpurities are addedimpurities are mixed from any flour using a papersievebeaker by a process called sieving. Sieving allows the tiny flour particles to pass through the holes of the sieveremain on the sieveremain on the holes of the sieve while the bigger impurities pass through the holes of the sieveremain on the holes of the sieveremain on the sieve. During the construction of a building, workers uses the sieving machine to mixrotary machine to addrotary sand sieving machine to filter the sand from stones and pebbles.