Directions: There are 20 blanks in the following passage. For each blank there are four choices marked [A] ,[B] ,[C] and [D] on the right side of the paper. You should choose the ONE that best fits into the passage. Then mark the corresponding letter on the Answer Sheet with a single line through the centre.

　　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 — without 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 a 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.

　　完形文章的出處：

　　Is There a Doctor Onboard?

　　As a physician who travels quite a bit, I spend a lot of time on planes listening for that dreaded " Is there a doctor onboard?" announcement. I've been called only once--for a woman who had merely fainted. But the incident made me curious about how often this kind of thing happens. I wondered what I would do if confronted with a real midair medical emergency--without access to a hospital staff and the usual emergency equipment. So when the New England Journal of Medicine last week published a study about in-flight medical events, I read it with interest.

　　The study estimated that there are an average of 30 in-flight medical emergencies on US flights every day. Most of them are not grave; fainting, dizziness and hyperventilation are the most frequent complaints. But 13% of them—roughly four a day--are serious enough to require a pilot to change course. The most common of the serious emergencies include heart trouble (46%), strokes and other neurological problems (18%), and difficulty breathing (6%).

　　Let's face it: plane rides are stressful. For starters, cabin pressures at high altitudes are set at roughly what they would be if you lived at 5000 to 8000 feet above sea level. Most people can tolerate these pressures pretty easily, But passengers with heart disease may experience chest pains as a result of the reduced amount of oxygen flowing through their blood. Low pressure can also cause the air in body cavities to expand -- as much as 30%. Again, most people won’t notice anything beyond mild stomach cramping. But if you've recently had an operation, your wound could open and if a medical device has been implanted in your body--a splint, a tracheotomy tube or a catheter--it could expand and cause injury. Another common in-flight problem is deep venous thrombosis--the so-called economy-class syndrome. when you sit too long in a cramped position, the blood in your legs tends to clot. Most people just get sore calves. But blood clots, left untreated, could travel to the lungs, causing breathing difficulties and even death. Such clots are readily prevented by keeping blood flowing; walk and stretch your legs when possible. Whatever you do, don’t panic. things are looking up on the in-flight-emergency front. Doctors who come to passengers' aid used to worry about getting sued; their fears have lifted somewhat since the 1998 Aviation medical Assistance Act gave them "good Samaritan" protection. and thanks to more recent legislation, flights with at least one attendant are starting to install emergency medical kits with automated defibrillators to treat heart attacks. are you still wondering if you are healthy enough to fly? if you can walk 150 ft. or climb a flight of stairs without getting winded, you'll probably do just fine. Having a Doctor close by doesn’t hurt, either.

　　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