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　　2、美国国家航空航天局表示，哈勃的主要任务之一就是帮助天文学家测定宇宙的准确年龄。现在，它已经顺利地完成了任务，帮助天文学家将宇宙的年龄精确到130亿至140亿年之间。天文学家用哈勃观测到仙女星座和其它星群中的造父变星(如图)，以确定宇宙的膨胀速度和宇宙的年龄。

　　2.According to NASA, "One of Hubble's key duties was to help astronomers determine a precise age for the universe. The telescope helped astronomers accomplish that goal, narrowing the universe's age to 13 to 14 billion years old. Astronomers made observations of Cepheid variable stars [pictured above]—pulsating stars used to measure vast distances—in the Virgo and other clusters to establish the expansion rate and the universe's age."

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