If the temperature at the earth's surface is twenty degrees Fahrenheit, the temperature in a coal mine 500 feet below the surface would, in degrees, be ______.

A．Vendors should lay great importance on service.
B．Hardware will account for a greater share of computer companies' revenue.
C．Trends of the 1990s in computer industry are difficult to predict.
D．Manufactures of monitors and printers will expand their business to automobile industry.

A．the trends of the 1990s in computer industry
B．the accelerating demands for software and service
C．computers industry's close link with auto-industry
D．the trends in the peripherals arena in the next decade