Supercooling human livers （肝臟） to -4 allows them to be kept three times as long before transplant （移植） compared with putting them on ice，US researchers say.That means organs （器官） can be kept for more than a day，which researchers say could revolutionize organ transplants.The next step will be to test how supercooled organs work in large animals such as pigs，before they are used on humans.
    The team at Massachusetts General Hospital and Harvard Medical School pioneered the technology in rats five years ago.However，there were difficulties going from a 10 g rat liver to a 1.5 kg human liver.As organs get bigger there is a greater danger of ice crystals （結(jié)晶） forming，which can harm jye.aim.The solution was to prepare the liver for supercooling by using a method that prevented freezing.Experiments on human livers showed they could be kept for 27 hours，rather than the nine hours when the organs are stored on ice. This could make it easier to perform liver transplants ----possibly saving hundreds of lives.
    One of the researchers，Dr Reinier de Vries，said：This is a big breakthrough in organ protection.The longer an organ can survive outside the body，the greater the chances of getting it to a patient that needs jye.ai.It also gives more time for tests to ensure the organ is a good match for the patient.
    The British Liver Trust said hundreds of people died every year waiting for a transplant.Pamela Healy，the charity's head，said：Finding new ways to increase the number of organs that can be used at any one time is important to decrease waiting times and increase the chance of a successful transplantation taking place.
    This research project into increasing the number of livers for transplant is jye.ailcomed.We await further research into this possibly exciting development.'

（1）How does the experiment revolutionize organ transplant？

C

C

A.It provides a way to prevent livers from being harmed.
B.It helps to transplant livers in large animals in a new way.
C.It allows livers for transplant to survive longer outside the body.
D.It ensures transplanted livers will work in very cold conditions.
（2）What does the underlined word "This" in Paragraph 2 refer to？

B

B

A.Livers can be stored for nine hours on ice.
B.Human livers can be kept for 27 hours.
C.Success in transplanting big organs.
D.Supercooling rat livers.
（3）What did Dr Reinier de Vries think of their experiment？

A

A

A.It increased the possibility of saving people.
B.It made liver transplants possible.
C.It drew much public attention.
D.It would be widely tested soon.
（4）What can we infer from Pamela Healy's words？

B

B

A.The research might not lead to success.
B.The research is important and should continue.
C.The development of organ transplanting is too slow.
D.The research is looking at many ways to keep livers.