см. тж. может использоваться ; не ~ ; успешно ~
• More than a million combines were then at work on American farms.
• We are active in the design and application of ...
• The machine has been functioning ( or operating , or working , or running ) properly.
• When the pump is in service ...
• The tubes operate at 350°C.
• The plant is operated 24 hours a day.
• The transformer performs well.
• The air grinder performs at 1/4 hp, 17,500 rmp, 100 psi.
• The belt can be run at speeds up to ...
• The adjustment can be made while the machine is running .
• Machines with this equipment are already in operation .