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阅读理解 It wasn't until Friends took off that Iwas a part of this extraordinary organization, St. Jude. And that was 25 yearsago. I am very honored to be a part of St. Jude and I've been in love with itever since. Right around this time every fall I get to spend the daywith a family of St. Jude. I always say it's the best day of the year and thehardest day of the year. And a few years back I met a little girl named Sawyer.She was seven at the time and I remember she had this pink little dress on andthese big angelic eyeballs. The chemo (化疗) had taken all of her hair and she hadthese t已知tan=4,cot=,则tan(a+)="(  " )A．B．C．D．