The Interstate Highway System has been an important part of the nation's economic growth during the past 40 years.

去过去40年间，州际公路系统对美国经济增长起着重要的作用。

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The Interstate Highway System has been an important part of the nation's economic growth during the past 40 years.

去过去40年间，州际公路系统对美国经济增长起着重要的作用。

youdao