(Reuters) - The post-surgery voice of British singer Adele was heard by U.S. television audiences on Friday as she sang an impressive a cappella version of her hit song, "Rolling In The Deep." The 23-year-old musician, who has not sung in public since vocal cord surgery, sang three verses of the hit in an excerpt of an upcoming "60 Minutes" profile that was shown on the "CBS This Morning" program. Her voice appeared back to its rich, soulful best. ...