In-facepiece dust concentration is changed dozens of times in a matter of minutes due to changes of the size of the gaps between the mask and face. Source. A respirator is a device designed to protect the wearer from inhaling particulate matter, including airborne microrganisms, fumes, vapors, i.e. gases.
Why join Brainly? A community for students. Products of the neolithic culture Steel plows Boats with sails Domesticated dogs Wild figs. the answer would mostly likely be referring to things that actually were of use to the neolithic people and agriculture was the biggest thing making the answer steel plow. anonymous.
The Mesolithic period in several areas shows a gradual transition from a food-collecting to a food-producing culture. The termination of the Neolithic period is marked by such innovations as the rise of urban civilization or the introduction of metal tools or writing. Again, the criteria vary with each case. The earliest known development of Neolithic culture was in SW Asia between 8000 B.C. and 6000 B.C.