51.   The U.S. trade died out as petroleum and synthetic materials replaced whale oil used to lubricate machinery and fuel lamps.

52.   We think of plastic -- its name from the Greek plastikos, meaning shapeable -- as the ultimate synthetic material, a landmark in the striving to outdo nature.

53.   Silicon carbide is a synthetic material used in the manufacture of refracting and abrasive products and by the steel industry.

54.   The minister said he hoped that over the next two or three years the availability of ocally-produced synthetic material would be doubled.