. >>> peter and caroline davis have been playing tennis since they were old enough to hold racquets. it's not just their athletic ability that makes this brother and sister team special. they are using their love of tennis to help change lives halfway around the world. it all started with the coach, teza. he's from zambia, a country in southern africa with a lot of poverty. more than half the population lives on less than $2 a day. >> i know how some kids don't -- unfortunately do not have enough activities and, you know, i -- and when i go to zambia i try to teach them tennis and i know how important tennis is to them because it was important to me. >> one day teza showed peter and caroline a photograph that forever changed their lives. >> it was just, the only time in my life when really a picture was worth a thousand words. there was a line of kids and all of them were wearing shoes and there were probably only two rackets for the entire line, and then we look around here, and we have all these extra rackets, and all this extra supplies just laying around. >> peter and caroline to