【单选题】As the cost of gas and oil for home heating has gone up, many Americans have switched from these fuels to wood for heating their homes. In 1973, approximately 200,000 wood-burning stoves, intended for...
A.
went up fivefold over a six-year period
B.
rose to seven million during the seventies
C.
multiplied thirty-five times between 1973 and the beginning of 1981