[单项选择]Nerve signals may travel through nerve or muscle fibers at speeds as high as two hundred miles per hour.
A. velocities
B. impulses
C. ratios
D. percentage

[单项选择]Fat cannot change into muscle______ changes into fat.


A. any more than
B. no more than
C. no less than
D. much more than

[单项选择]Travel medicine in Britain is


A. not something anyone wants to run.
B. the responsibility of the government.
C. administered by private doctors.
D. handled adequately by travel agents.

[单项选择]How does the writer feel about travel today

[单项选择]The main interest of travel companies dealing with travel medicine is to


A. prevent people from falling ill.
B. make money out of it.
C. give advice on specific counties.
D. get the government to pay for it.

[单项选择]Strange things happen to time when you travel because（）
A. no day really has twenty-four hours
B. the earth is divided into time zones
C. time zones are not all the same size
D. no one knows where time zones begin

[单项选择]People will only think better of travel medicine if


A. it is given more resources by the government.
B. more accurate information on its value is available.
C. the government takes over responsibility from the NHS.
D. travellers pay more attention to the advice they get

[单项选择]

Most people who travel long distance complain of jet-lag. Jet-lag makes business travelers less productive and more prone (21) making mistakes. It is actually caused by (22) of your "body clock" a small cluster of brain cells that controls the timing of biological (23) . The body clock is designed for a (24) rhythm of daylight and darkness, so that it is thrown out of balance when it (25) daylight and darkness at the "wrong" times in a new time zone. The (26) of jet-lag often persist for days (27) the internal body clock slowly adjusts to the new time zone.
Now a new anti-jet-lag system is (28) that is based on proven (29) pioneering scientific research. Dr. Martin Moore-Ede had (30) a practical strategy to adjust the body clock much sooner to the new time zone (31) controlled exposure to bright light. The time zone shift is easy to accomplish and eliminates (32) of the
A. specific
B. complicated
C. unique
D. peculiar