阅读下面短文，从短文后各题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。To personal trainer Sammy Callari, 13-year-old Parker Seward is more than a client (客户). He's his "little brother. Over the past year, the pair have developed a close 1 . They play basketball together, share meals and dance to hip-hop like no one's watching.
Last spring the trainer was asked to work with Parker, who had Down syndrome (唐氏综合症), 2 his co-worker (was out of town. Callari had never worked with someone with a (n) 3 by himself before. He was stressed the first day he met Parker, but Parker's wide smile and cheerful introduction made him 4 at once.
Parker reminded Callari of himself when he was a (n) 5 . As a high schooler, Callari described himself as a weak, thin kid. When it came to sports, he always 6 to be noticed. His dream of playing basketball in college quickly died. He then turned to another new7 . His younger brother trained him to become a Kung fu artist. Callari took part in five matches. Out of those fights he was considered to be the 8 , but he won three times.
"Society tells you ‘you can't do this', or ‘you can't do that', "says Callari. When it comes to Parker, Callari 9 to accept the word "can't".
The friends meet twice a week to train. They train together with biking and boxing. Parker has a short 10 span (持续时间), so it's Callari's job to keep him focused. Callari 11 videos of himself and Parker's exercising online-12 , with the agreement from Parker's mom.
"It's clear that it is Parker who 13 me," Callari says. "He's made me a better trainer, and he's also made me a better person," Callari adds. "A lot of people see him as different, but I've 14 looked at him like that. If anyone is 15 , it's me."
