He spent at least two-thirds of his more than, about three-quarters of his time in the northern states.

他至少花费了他旅程的三分之二,可能不止,应该是他旅程的四分之三时间,周游于北方各州

耶鲁公开课 - 美国内战与重建课程节选

So, one plus three is four, four sixths, which leaves two sixths, or one third.

加上3是4，六分之四，还剩六分之二，也就是三分之一。

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