In 1914 a total of 469,000 cars and trucks were produced in the United States, but in 1929 almost twice the numbers of trucks alone came off the assembly lines.
A. the numbers of trucks alone
B. that number of trucks alone
C. the number of trucks by themselves
D. as many trucks themselves
E. as many trucks by themselves
求问b中alone放在这里是什么意思，有什么作用？
作者: 绝望的小老鼠 时间: 2013-4-28 15:56
“单独这一项（just）” 的意思~~~ 修饰number，起强调作用。 注意到but 在暗示对比（1914和1912的车的生产值的对比）
A number不能加s，否则指的是那个具体的数值中的数字，这里句子本意是强调整体的数值。 the使用有误，因为that用于指代前面的a total of 46900 cars
C中number不能被by themselves修饰
DE 错误是因为卡车不可能自己生产by themselves 前面略掉了were produced（比较句可以省略前面出现过的成分）