题目内容：
共用题干Chest Compressions:Most Important of CPR
Cardiopulmonary resuscitation,or CPR,can save the life of someone whose heart has stopped .The condition is called cardiac arrest. The heart stops pumping blood. The person stops breathing. Without lifesaving measures,the brain starts to die within four to six minutes.CPR combines breathing into the victim's mouth and repeated presses on the chest.______(46).
However,a new Japanese study questions the usefulness of mouth-to-mouth breathing. The study was published in the British medical magazine,The Lancet. Doctors in Tokyo led the re- search .It examined more than four thousand people who had suffered cardiac arrest. In all the cases,witnesses saw the event happen.
More than one thousand of the victims received some kind of medical assistance from witnes- ses .Seven hundred and twelve received CPR.Four hundred and thirty-nine received chest pres- ses only.______(47)The researchers say any kind of CPR improved chances of the patient's survival. But,they said those people treated with only chest presses suffered less brain damage. Twenty-two percent survived with good brain ability.______(48).
The American Heart Association changed its guidelines for CPR chest presses in 2005.
______(49)Gordon Ewy is a heart doctor at the University of Arizona College of Medicine in Tucson. He wrote a report that appeared with the study.Doctor Ewy thinks the CPR guidelines should be changed again.He said the heart association should remove rescue breaths from the guidelines. He argues that more witnesses to cardiac arrests would provide treatment if rescue breaths are not a part of CPR. He says this would save lives______(50).
Cardiac arrest kills more than 300,000 people in the United States every year. The American Heart Association says about ninety-five percent of victims die before they get to a medical center.
______(46)
A: Sofar,we have not known exactly yet whether mouth-to-mouth breathing is really useless in CPR.
B: Only ten percent of the victims treated with traditional CPR survived with good brain a-bility.
C: CPR keeps blood and oxygen flowing to the heart and brain.
D: His studies show that many people do not want to perform mouth-to-mouth breathing on a stranger for fear of getting a disease.
E: It said people should increase the number of chest presses from fifteen to thirty for every two breaths given.
F: No mouth-to-mouth rescue breaths were given to them.
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