What is the tallest structure in the Western Hemisphere?
The CN Tower in Toronto, Ontario, Canada is the tallest free-standing structure in the Western Hemisphere. It was completed in 1976, and was the tallest structure in the world from 1975 until 2007, when it was surpassed by the Burj Khalifa.
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(Optional) Context information is below.
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Answer the following query.
What is the tallest structure in the Western Hemisphere?

user
The CN Tower in Toronto, Ontario, Canada is the tallest free-standing structure in the Western Hemisphere. It was completed in 1976, and was the tallest structure in the world from 1975 until 2007, when it was surpassed by the Burj Khalifa.
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