动脉把血液从心脏输送出去。

___Arteries carry blood away from the heart.

这条街是城市的主要干道之一。

This street is one of the city's main ___arteries.

这条主干道是城市交通系统的重要动脉。

This main road is a vital ___artery in the city's transportation system.

高速公路是这个国家经济的大动脉。

The highways serve as the economic ___arteries of this country.