完形填空

　　American teenagers have always worked for extra pocket money．　　1　　 their predecessors(前辈), today’s young people are 　　2　　 to work long hours during the week for hundreds of dollars each month．They spend the money 　　3　　 themselves rather than contributing it 　　4　　 their families．In a 1997 　　5　　 of 16 000 high school seniors nationwide, it was 　　6　　 that eighty percent of students who worked 　　7　　 their earnings on their own 　　8　　, such as clothing, stereo equipment, records and movies．　　9　　 five percent said they contributed most of their income, which often exceeded, ＄200 a month, to help pay family living 　　10　　．The benefits of this work-and-spend ethics(伦理观)are being 　　11　　 argued．Some experts, and many parents, 　　12　　 that year-round part-time employment increases youngsters’ 　　13　　 of worth, teaches them financial(财政的) 　　14　　 and reduces tension, and thus conflict(冲突) 　　15　　 the family．Other, 　　16　　, argue that working teenagers are separated, physically and financially, 　　17　　 their families, which in turn 　　18　　 parental authority．

　　Teenagers’ schoolwork can also suffer．“When youngsters 　　19　　 for luxuries, they are buying distraction 　　20　　 education,” said a program director for the U．S．Department of Education．Working teenagers themselves say they have less time to spend with their friends and families．

阅读理解

　　Thinking of throwing your old cell phone?Think again．Maybe you should mine it first for gold, silver and other metals．It’s called“urban mining”, searching through the small pieces of metal in electronic products for gold, silver and other expensive metals．It is a growing industry around the world as prices for metal grow higher and higher．

　　The gold and other precious metals from electronic products are melted down and then sold．The metals can be made into jewelry or circuit(电路)for mobile phones．“It can be precious, so we want to recycle whatever we can,”said Tadahiko Sekigawa, president of Eco-System Recycling Co．Ltd．

　　A ton of ore(矿石)from a gold mine produces just 5 grams of gold on average, while a ton of mobile phones can give 150 grams or more, according to a study by Yokohama Metal Co-Ltd．, another recycling company．The same amount of useless mobile phones also contains around 100 kg of copper and 3 kg of silver, among other metals．

　　Recycling has become more important because prices of metals have hit record highs．Eco-Systems, opened 20 years ago near Tokyo, usually produces about 200 to 300 kg of gold bars a month, worth about ＄5.9 million to ＄8.8 million．That’s about the same as a small gold mine．

阅读理解

　　In the United Statcs, there were some well-constructed houses for native Indians, ranging from the simple brush shelter to the five-storied pueblo．

　　In the eastem United States, one of the existing types was that commonly know under the Algonkian name of wigwam in which the Iroquois Indians lived．The wigwams were of wagon-top shape with straight sides and ends, made by bending young trees to form the round shape．Over this shape pieces of tree bark were laid to protect the Indians from bad weather．Over the bark dried grass was added．A small hole allowde smoke to escape from the top．Doorways at each en served also as windows, The Iroquois Indians built trunk walls all around their villages．The wall had only one opening, They could quickly close this cpening if their enemies came near．

　　Interestingly, the Choctaw Indians in Mississippi also lived in a wigwam of a most primitive(原始的)construction, but different from those of the Iroquois Indians．The Choctaw Indians'wigwams, made from mud,cane and straw, were in the form of a bee-hive．The covering was made of a long, tough grass．A post in the centre supported the roof．A hole in the top admitted the light, and allowed the smoke to pass out．

　　The tipi tent-housing of the upper lake and plains area was put up with poles set lightly in the ground, tied together near the top, and covered with bark and grass in the lake country．It was easily portable, and two women could set it up or take it down within an hour．

　　The Pawnee, Mandan and other Indian tribes(部落)along the Missouri built solid ring-shaped structhures of trunk, covered with earth and dried grass,housing adozen families．

　　The Wichita and other tribes of the Texas border built large ring-shaped houses covered with dried grass．

　　Apart from the regular housing, almost every tribe had some style of housing．