Заполните пропуски предлогами by, with, for, at, in. the steam was invented watt, who worked years before he could make the instruments he perfected his machine. .first he worked tools so he could not make his engine well-regulated. the old machine was kept going boy who stood by it and the air of which the steam was condensed at every revolution. .this machine, though it was imperfect, some work was done and it had been used large mine-owner (шахтовладелец) to pump out the water. the first efficient steam-engine was made birmingham firm and it was soon every manufacturer. the revolution in industry made machine was extremely great.