Dried foodCenturies ago, man discovered that removing moisture from food helps to preserve it, and that tile easiest way to do this is to expose the food to sun and wind. In this way the North American indians produce pemmican (dried meat ground into powder and made into cakes), the Scandinavians make stockfish and the Arabs dried dates and ’apricot leather. ’All foods contain water—cabbage and other leaf vegetables contain as much as 93% water, potatoes and other root vegetables 80%, lean meat 75% and fish anything from 80% to 60% depending on how fatty it is. If this water is removed, the activity of the bacteria which cause food to go bad is checked.Fruit is sun-dried in Asia Minor, Greece, Spain and other Mediterranean countries, anti also in California, South Africa anti Australia. The methods used vary, but in general, the fruit is spread out on trays in drying yards in the hot sun. In order to percent darkening, pears, peaches and apricots are exposed to the fumes of burning sulphur before drying. Plums, for making prunes, and certain varieties of grapes for making raisins and currants, are dipped in an alkaline solution in order to crack the skins of the fruit slightly and remove their wax coating, so increasing the rate of drying.Nowadays most foods are dried mechanically. The conventional method of such dehydration is to put food in chambers through which hot air is blown at temperatures of about 110℃ at entry to about 43℃ at exit. This is the usual method for drying such things as vegetables, minced meat, and fish.Liquids such as milk coffee, tea, soups and eggs may be dried by pouring them over a heated horizontal steel cylinder or by spraying them into a chamber through which a current of hot air passes. In the first case, the dried material is scraped off the roller as a thin film which is then broken up into small, though still relatively coarse flakes. In the second process it falls to the bottom of the chamber as a fine powder. Where recognizable pieces of meat and vegetables are required, as in soup, the ingredients are dried separately and then mixed.Dried foods take up less room and weigh less than the same packed in cans or frozen, and they do not need to be stored in special conditions. For these reasons they are invaluable to climbers, explorers and soldiers in battle, who have little storage space. They are also popular with housewives because it takes so little time to cook them. Usually it is just a case of replacing the dried-out moisture with boiling water. The conventional method of dehydration is to ().
A. expose food to sun
B. expose food to wind
C. dip food in an alkaline solution
D. put food in certain chambers through which a current of very hot air passes
Can the Internet help patients jump the line at the doctor’s office The Silicon Valley Employers Forum, a sophisticated group of technology companies, is launching a pilot program to test online "virtual visits" between doctors at three big local medical groups and about 6 000 employees and their families. The six employers taking part in the Silicon Valley initiative, including heavy hitters such as Oracle and Cisco Systems, hope that online visits will mean employees won’t have to skip work to tend to minor ailments or to follow up on chronic conditions. "With our long commutes and traffic, driving 40 miles to your doctor in your hometown can be a big chunk of time, "says Cindy Conway, benefits director at Cadence Design Systems, one of the participating companies.Doctors aren’t clamoring to chat with patients online for free; they spend enough unpaid time on the phone. Only 1 in 5 has ever e-mailed a patient, and just 9 percent are interested in doing so, according to the research firm Cyber Dialogue. "We are not stupid," says Stifling Somers, executive director of the Silicon Valley employers group. "Doctors getting paid is a critical piece in getting this to work." In the pilot program, physicians will get $20 per online consultation, about what they get for a simple office visit.Doctors also fear they’ll be swamped by rambling e-mails that tell everything but what’s needed to make a diagnosis. So the new program will use technology supplied by Healinx, an Alameda, Calif-based star-up. Healinx’s "Smart Symptom Wizard" questions patients and turns answers into a succinct message. The company has online dialogues for 60 common conditions. The doctor can then diagnose the problem and outline a treatment plan, which could include e-mailing a prescription or a face-to-face visit.Can e-mail replace the doctor’s office Many conditions, such as persistent cough, require a stethoscope to discover what’s wrong and to avoid a malpractice suit. Even Larry Bonham, head of one of the doctor’s groups in the pilot, believes the virtual doctor’s visits offer a "very narrow" sliver of service between phone calls to an advice nurse and a visit to the clinic.The pilot program, set to end in nine months, also hopes to determine whether online visits will boost worker productivity enough to offset the cost of the service. So far, the Internet’s record in the health field has been underwhelming. The experiment is "a huge roll of the dice for Healinx", notes Michael Barrett, an analyst at Internet consulting firm Forester Research. If the "Web visits" succeed, expect some HMOs (Health Maintenance Organizations) to pay for online visits. If doctors, employers, and patients aren’t satisfied, figure on one more E health star-up to stand down. What can be learned about the online doctors’ visits().
A. They are a quite promising business.
B. They are funded by the local government.
C. They are welcomed by all the patients.
D. They are very much under experimentation.
Music is often divided into several categories, or groups. Some of the categories are: classical music, traditional music, rock music, and jazz music.The first kind, classical music, refers to orchestra music that originated in Europe a few hundred years ago. Most of the original classical music was composed, or written, in Italy, Germany, Austria, or Russia. Beethoven and Bach were two famous composers of classical music. Classical music is usually played by a variety of string instruments, such as the violin, and by a variety of wind instruments such as the flute.The second type of music is traditional music. Traditional music is music that comes from a particular culture. Every culture has its own special forms of traditional music. For example, "blues" music is one kind of traditional music in the United States and "enka" music is one kind of traditional music in Japan. Each culture has its own traditional music, and its own special instruments for playing its trditional music.Another kind of music is rock music. Rock is generally a loud kind of music, played with a strong beat. Rock musicians often use electric instruments, such as electric guitars and electric pianos, but other instruments can also be used. Rock music probably began in Europe about 30 or 40 years ago. Rock became very popular, especially among young people, during the 1960s and 1970s.The fourth kind of music is jazz. Jazz probably comes from Africa originally. Jazz has a different kind of rhythm from other kinds of music. A variety of musical instruments are used to play this kind of music, especially wind instruments such as the trumpet and saxophone. Often piano, brass, and a variety of percussion instruments are also used. What do we call music that comes from a particular culture().
A. jazz music
B. classical music
C. traditional music
D. rock music
Music is often divided into several categories, or groups. Some of the categories are: classical music, traditional music, rock music, and jazz music.The first kind, classical music, refers to orchestra music that originated in Europe a few hundred years ago. Most of the original classical music was composed, or written, in Italy, Germany, Austria, or Russia. Beethoven and Bach were two famous composers of classical music. Classical music is usually played by a variety of string instruments, such as the violin, and by a variety of wind instruments such as the flute.The second type of music is traditional music. Traditional music is music that comes from a particular culture. Every culture has its own special forms of traditional music. For example, "blues" music is one kind of traditional music in the United States and "enka" music is one kind of traditional music in Japan. Each culture has its own traditional music, and its own special instruments for playing its trditional music.Another kind of music is rock music. Rock is generally a loud kind of music, played with a strong beat. Rock musicians often use electric instruments, such as electric guitars and electric pianos, but other instruments can also be used. Rock music probably began in Europe about 30 or 40 years ago. Rock became very popular, especially among young people, during the 1960s and 1970s.The fourth kind of music is jazz. Jazz probably comes from Africa originally. Jazz has a different kind of rhythm from other kinds of music. A variety of musical instruments are used to play this kind of music, especially wind instruments such as the trumpet and saxophone. Often piano, brass, and a variety of percussion instruments are also used. Which instrument is not used to play jazz music().
A. saxophone
B. piano
C. violin
D. trumpet