试题出自试卷《广西大学2013年考博英语真题》

Most people who travel long distances complain of jetlag (时差).Jetlag makes business travelers less productive and more prone（1）making mistakes. It is actually caused by（2）of your “body clock" - a small cluster of brain cells that controls the timing of biological（3）. The body clock is designed for a regular rhythm of daylight and darkness, so that it is thrown out of balance when it（4）daylight and darkness at the “wrong” times in a new time zone. The symptoms of jetlag often persist for days（5） the internal body clock slowly adjusts to the new time zone.
Now a new anti-jetlag system is（6）that is based on proven tentative pioneering scientific research. Dr. Martin Moore has（7）a practical strategy to adjust the body clock much sooner to the new time zone（8）controlled exposure to bright. The time zone shift easy to accomplish and eliminates （9）of the discomfort of jetlag.
A successful time zone shift depends on knowing the exact times to either（10）or avoid bright light. Exposure to light at the wrong time can actually make jetlag worse. The proper schedule（11）light exposure depends a great deal on specific travel plans. Data on a specific flight itinerary (旋行路线)and the individual's sleep （12） are used to produce a Trip Guide with instructions on exactly when to be exposed to bright light.
When the Trip Guide calls（13）bright light you should spend time outdoors if possible. If it is dark outside, or the weather is bad, （14）you are on an aero plane, you can use a special light device to provide the necessary light（15）for a range of activities such as reading, watching TV or working.