As a physician who travels quite a lot, I spend a lot of time on planes listening for that dreaded "Is there a doctor on board?" announcement. I've been 71 only once - for a woman who had

　　merely fainted. But the 72 made me quite curious about how 73 this kind of thing happens I wondered what I would do if 74 with a real midair medical emergency-with out access 75 a hospital staff and the usual emergency equipment. So 76 the New England Journal of Medicine last week 77 a study about in -flight medical events. I read it 78 interest.

　　The study estimated that there are a(n) 79 of 30 in-flight medical emergencies on U.S. flights every day. Most of them are not 80;fainting and dizziness are the most frequent complaints. 81 13% of them -roughly four a day - are serious enough to 82 a pilot to change course. The most common of the serious emergencies 83 heart trouble. strokes, and difficulty breathing.

　　Let's face it: plane rides are 84.For starters, cabin pressures at high altitudes are set at roughly 85 they would be if you lived at 5,000 to 8,000 feet above sea level. Most people can tolerate these pressures pretty 86 ,but passengers with heart disease 87 experience chest pains as result of the reduced amount of oxygen flowing through their blood. 88 common in-flight problem is deep venous thrombosis - the so-called economy class syndrome (綜合癥).89 happens, don't panic. Things are getting better on the in-flight-emergency front. Thanks to more recent legislation, flights with at 90 one attendant are starting to install emergency medical kits to treat heart attacks.

　　71 A)called C)Informed

　　B)addressed D)surveyed

　　72 A)Accident C)incident

　　B)condition D)disaster

　　73 A)soon C)many

　　B)long D)often

　　74 A)confronted C)identified

　　B)treated D)provided

　　75 A)for C)by

　　B)to D)through

　　76 A)before C)when

　　B)since D)while

　　77 A)collected C)discovered

　　B)conducted D)published

　　78 A)by C)with

　　B)of D)in

　　79 A)amount C)sum

　　B)average D)number

　　80 A)significant C)common

　　B)heavy D)serious

　　81 A)For C)But

　　B)On D)So

　　82 A)require C)engage

　　B)inspire D)command

　　83 A)include C)imply

　　B)confine D)contain

　　84 A)enjoyable C)tedious

　　B)stimulating D)stressful

　　85 A)who C)which

　　B)what D)that

　　86 A)harshly C)easily

　　B)reluctantly D)casually

　　87 A)ought to C)used to

　　B)may D)need

　　88 A)Any C)Other

　　B)One D)Another

　　89 A)Whatever C)Whenever

　　C)Whichever D)Wherever

　　90 A)most C)least

　　B)worst D)best