Use the local language of that country, to show respect for their culture. This also allows you to "copy" the text on your American site without it being duplicate content, since the language will be different.

Remember that Europe is a continent, not a nation. There is a different language and a different culture in each country. Their countries are the size of American states, and crossing borders is now easy, but you must not treat all Europeans as being the same. Italy is not Denmark.

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Sincerely, Jacob
SEO Houston
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