Помогите пожалуйста ! Выписать все сказуемые из текста и определить их видовременную форму.Several of these larger distributors have been in the gas
business since the middle-to-late 1800s , selling gas manufactured from coal for home heating and cooking , or augmenting local reserves of natural gas with supplies imported from the United States. With the completion of the major transmjssion lines to the west coast and eastern Canada , these utilities were able to switch from manufactured to natural gas or to add western Canadian natural gas to their local production or imported volumes . Inthe case of consumers burning manufactured gas the utilities had to convert many of the existing appliances so they could operate at peak efficiensy using the higher heating value contained in natural gas . The change - over was accomplished within two years of the availaility of Alberta natural gas ; and by 1960 the conversion from manyfactured gas to natural gas was completed in eastern Canada where most of the manufactured gas was consumed .