2．Cut out part of a healthy person's liver and transplant it into a sick person--it sounds like a complicated and dangerous operation，not to mention very expensive．But it is sometimes the only possible cure for a seriously ill patient with liver disease． Until now British scientists have just announced a new stem cell technique，which allows them to grow healthy liver cells outside human bodies．According to the researchers，it could be another five to 10 years before the technique can actually be used to help patients with liver disease．However，they say the method might one day replace liver transplants altogether．The study was led by the University of Cambridge and the Welcome Trust Sanger Institute，a British genomics and genetics research institute．It was published in the journal nature on October 12，2011． The researchers took skin cells from a patient with a mutation （变异） in a gene called alphal-antitrypsin （a-l抗胰蛋白酶）．This gene makes a protein that protects our bodies against inflammation （炎症）．People with changed or damaged alphal-antitrypsin are not able to release the protein correctly from the liver，so the protein is trapped there and eventually leads to liver cirrhosis （肝硬化）． Scientists then used an advanced technique to cut away the faulty section of DNA from a stem cell and replace it with a corrected one，according to the journal．The stem cells went on to produce fresh and healthy liver cells with normal protein levels．Scientists put the new liver cells into mice and found that they worked very well． Stem cells are the life source of all other cells in the body．They could transform medicine，providing treatment for blindness，spinal cord injuries and other serous injuries．They could also be used to produce new cells for damaged organs． David Lomas，a Cambridge biology professor who worked on the team，said："If we can use a patient's own skins cells to produce liver cells that we can put back into the patient，we may prevent the future need for transplantation．" 71．what is the best title of this passage？D A．How to transplant liver for patients B．A new way to transplant livers for patients C．The difficulty in curing liver patients D．New life for liver patients 72．The first paragraph is written toC． A．show how difficult it is to cure liver disease B．tell us what a liver transplant involves C．introduce a potential cure for liver disease D．show how serious liver disease can be 73．Why do some people get liver cirrhosis according to the article？C A．Because their bodies are lacking in alphal-antitrypsin． B．Because their skin cells are not able to protect against inflammation． C．Because the alphal-antitrypsin in their bodies is changed or damaged． D．Because their liver releases too high a level of protein． 74．According to British scientists，liver transplant mightA． A．become history sooner or later B．be replaced by a new stem cell technique in five years C．be the only possible cure liver disease in the future D．be prevented in the future 75．What can be inferred from the passage？D A．Stem cells can keep liver cells healthy and fresh． B．Equaling medicine，stem cells can cure blindness，spinal cord injuries and other serous injuries C．Stem cells can replace the damaged organs． D．All other cells in the body can't work well without stem cells．
