
Are the following mentions coreferent?:
<m> replacing </m> in On Saturday, the 26-year-old was handed the keys to the Tardis when he was unveiled as the 11th Doctor Who, replacing David Tennant, who steps down later this year. 
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<m> takes a look </m> in With young British actor Matt Smith stepping into Doctor Who's title role, Wired.com takes a look back at the 10 actors who have previously portrayed sci-fi TV's most enduring hero. 