Classmates of injured Chinese student Zhou Danling arrive at the Boston Medical Center in Boston, the United States, April 16, 2013. Zhou, who was injured during the Boston marathon blasts, turned into better condition from critical one after receiving two surgeries. (Xinhua/Wang Lei)

Dr. Tracey Dechert (L) introduces medical measures for injured Chinese student Zhou Danling and other injured people at the Boston Medical Center in Boston, the United States, April 16, 2013. Chinese student Zhou Danling, who was injured during the Boston marathon blasts, turned into better condition from critical one after receiving two surgeries. (Xinhua/Wang Lei)

Dr. Tracey Dechert (C) introduces medical measures for injured Chinese student Zhou Danling and other injured people at the Boston Medical Center in Boston, the United States, April 16, 2013. Chinese student Zhou Danling, who was injured during the Boston marathon blasts, turned into better condition from critical one after receiving two surgeries. (Xinhua/Wang Lei)

Chinese Vice Counselor-General Zhong Ruiming (R) of the Chinese Consulate General in New York helps local Chinese people contact with their relatives and friends at the Boston Medical Center in Boston, the United States, April 16, 2013. Chinese student Zhou Danling, who was injured during the Boston marathon blasts, turned into better condition from critical one after receiving two surgeries. (Xinhua/Wang Lei)

Chinese Vice Counselor-General Zhong Ruiming (R) and counselor Zhou Maoyi of the Chinese Consulate General in New York discuss with each other about the injured Chinese student and other casualties at the Boston Medical Center in Boston, the United States, April 16, 2013. Chinese student Zhou Danling, who was injured during the Boston marathon blasts, turned into better condition from critical one after receiving two surgeries. (Xinhua/Wang Lei)

Chinese Vice Counselor-General Zhong Ruiming (R) of the Chinese Consulate General in New York shows words written by injured Chinese student Zhou Danling at the Boston Medical Center in Boston, the United States, April 16, 2013. The words read "Everything is fine. Don't Worry." Zhou, who was injured during the Boston marathon blasts, turned into better condition from critical one after receiving two surgeries. (Xinhua/Wang Lei)