阅读下面短文，从短文后各题所给的四个选项（A、B、C、D）中，选出可以填入空白处的最佳选项。
What do you think of that? One man donated(捐赠) his stem cells (干细胞)to a(n) 1 living on the other side of the world.
A man working as a taxi driver in Shanghai 2 an activity about stem cell donation. Shortly after, he received the 3 that his stem cells had been matched to a boy in England. The receiver is just seven years old. The driver, Jiang Yongfeng, 4 to donate his stem cells at once. “I did not expect it to happen so 5. I was so excited to get a match so soon.” He says. “6 I learned the boy was only born in 2008, I was silent. And I 7 I made the right decision. I must help him.”
Some people 8 stem cell transplants to treat cancer. They must 9 a donor with nearly the same genes(基因). It means the matched 10 must have the very similar gene. The possibility of the long-distance match between Jiang Yongfeng and the little boy is 11. It sounds like a 12miracle（奇迹）. “ The little boy receiving Jiang's donation is very 13, ” doctors said.
Some donors were 14 to donate stem cells in out-dated ways because of poor health care systems years ago. It was a(n) 15 experience that many people couldn't stand. 16, Mr. Jiang was able to use a simpler and safer method.
Usually donors and receivers do not meet, nor do they know each other's 17. Does Jiang Yongfeng mind that he doesn't even know the little boy's name? “ No,” he shakes his 18. “ I just want the operation to be done as soon as possible so that they can send my 19 to the UK and help the little kid 20 as soon as possible. I hope he can be brave and strong and that he can live a good life.
