Detailed Instructions: In this task, given a sentence in the English language, your task is to convert it into the Japanese language.
Q: He estimates that nearly two-thirds of the 278,000 yearly flights between Canadian cities cross over the U.S. border.
A:
彼は年間278,000便の約三分の二が、米国の国境上を横切ってカナダの都市間を飛行すると推定している。