Surgeons in Spain have successfully carried out the world's first organ transplant (移植) using new stem cell technology. Some people are calling it the greatest medical breakthrough so far this century. But what are stem cells? As we know, most cells in our bodies are designed____ -for example, a liver cell develops to work in the liver and cannot become a heart cell. But stem cells are different. They are very young and in the laboratory scientists can grow them into different types of cells. Claudia Castillo needed a new windpipe (气管) after getting a serious disease. Scientists from the University of Bristol took a donor windpipe, from someone who had recently died. They used strong chemicals to remove the donor's cells, leaving a tissue scaffold (组 织支架). This was refilled with cells from Ms Castillo's windpipe and stem cells from her bone. After four days the cells had grown sufficiently for the windpipe to be transplanted into Ms Castillo. Currently, transplant patients have to take drugs for the rest of their lives to prevent their bodies rejecting the new organs. These drugs can have bad side-effects, and do not always prevent rejec tion. But by using Ms Castillo's own cells, doctors were able to trick her body into thinking the new windpipe was her own organ. Five months on, Claudia Castillo is in perfect health. This ground-breaking procedure could be used in other trans- plant operations in the future. Scientists also believe stem cells might be used to treat Parkinson's disease, heart disease, stroke, ar thritis, burns and so on. However, stem cell research is extremely controversial. The most effective stem cells do not come from adults but from embryos (胚胎) created in laboratories which are just a few days old. Many people have religious or ethical objections to growing embryos, even if they can be used to cure diseases.
1. What's the best title for the passage? ( Please answer within 8 words. ) ______________________________________________________________________________________ 2. Fill in the blank in Paragraph 2 with proper words. ( Please an swer within 8 words. ) ______________________________________________________________________________________ 3. Which sentence in the text is the closest in meaning to the fol lowing one? However, Ms Castillo's body mistook the new windpipe for her own because doctors put her own cells in it. ______________________________________________________________________________________ 4. What do you think of the stem cell transplant? Why? ( Please answer within 30 words. ) ______________________________________________________________________________________ 5. Translate the underlined sentence in Paragraph 4 into Chinese. _______________________________________________________________________________________
