The dry mountain ranges of the western United States contain rocks dating back 440 to 510 million years, to the Ordovician period, and teeming with evidence of tropical marine life.

美国西部干燥的山脉包含了距今4.4亿至5.1亿年前的奥陶纪岩石，其中充斥着热带海洋生物生存的迹象。

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The HART system is being considered by United States Marine Corps, Army, Navy, Air Force and special operations.

据悉，美国海军陆战队，陆军，海军，空军和特种作战等机构正在考虑是否使用HART系统。

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I served 22 years in the United States Marine Corps.

我在美国海军陆战队服役了22年。

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The memorial honors all members of the United States Marine Corps who died in battle since the American Revolution.

VOA: special.2010.05.31

Marine Sergeant Colin Archipley returned to the United States after serving three tours of duty in Iraq.

VOA: special.2010.12.28

In one video, a United States Marine officer named Steve Conteaguero reads a poem.

VOA: special.2011.01.31

Petersen is a veteran fighter pilot who served 38 years in the United States Marine Corps.

WHITEHOUSE: President Obama Announces More Key Administration Posts

John Schaeffer, is Keeping Faith: A Father-Son Story About Love and the United States Marine Corps.

CENTERFORSECURITYPOLICY: What We Have To Be Thankful For: Our Men And Women In Uniform

My father loved his country and was immensely proud of his service in the United States Marine Corps.

FORBES: The NRA's Communications Crisis