In the past, Americans got their calories mainly from______. A．healthy carbohydrate B．meat, eggs, and dairy C．breads, cereals and pasta D．yogurts, crackers and cookies
A. A．healthy B.meat, C.breads, D.yogurts,
【参考答案】
B 根据出题顺序、Americans、calories等信息对应到第三段。该段最后一句指出：From1977to......