填空题

Doctors perform transplant operations to replace tissue or organs in a person who is sick or injured. Organ transplants help save (36)________of lives each year. The year of 2004 marked the (37)________anniversary of the first successful transplant of a human organ. An American medical team performed the first successful organ transplant on December 23, 1954. The patient, Richard Herrick, was (38)________ from a kidney (39)________. Doctor Joseph Murray gave Richard a kidney from his twin brother, Ronald. Ronald had the same (40)________as Richard. Richard survived for eight more years with the kidney. In 1990, Doctor Murray was given the Nobel Prize in Medicine for his work. The first transplant operation was carried out in (41)________. A German doctor placed skin from a woman’’s leg on her nose. By 1863, a (42)________ scientist showed that the body rejects tissue transplants from one person to another. Forty years later, a German scientist found that this rejection was carried out by the body’’s defense system (43)________the foreign tissue. Rejection continued to be a problem well into the 20th century. In 1958, French doctor Jean Dausset discovered a system for tissue matching. (44)________________________. In 1972, Swiss scientist Jean Borel discovered that the drug cyclosporine (环孢菌素)could stop the body from rejecting the new organ or tissue. (45)________________________. Experts say (46)________________________.