题目内容：
自1978年经济改革以来，中国经济以年均近10%的速度增长，使其国民生产总值几乎翻了两番。A. Since economic reform began in 1978, an average growth rate of almost 10% a year has seen China’s GNP nearly double.
B. Since economic reform began in 1978, an average growth rate of almost 10% a year has seen China’s GNP nearly quadruple.
C. Since economic reform in 1978, China’s economy grows at a rate of almost 10% a year and makes GDP nearly double.
D. Since economic reform in 1978, China’s average growth rate is almost 10% a year and has witnessed its GDP quadruple.
参考答案：