16．As any homemaker who has tried to keep order at the dinner table knows，there is far more to a family meal than food．Sociologist Michael Lewis has been studying 50families to find out just how much more． Lewis and his co-workers carried out their study by videotaping （录像） the families while they ate ordinary meals in their own homes．They found that parents with small families talk actively with each other and their children．But as the number of children gets larger，conversation gives way to the parents'efforts to control the loud noise they make．That can have an important effect on the children．"In general the more question-asking the parents do，the higher the children's IQ scores，"Lewis says．"And the more children there are，the less question-asking there is．" The study also provides an explanation for why middle children often seem to have a harder time in life than their siblings （兄弟姐妹）．Lewis found that in families with three or four children，dinner conversation is likely to center on the oldest child，who has the most to talk about，and the youngest，who needs the most attention．"Middle children are invisible，"says Lewis．"When you see someone get up from the table and walk around during dinner，chances are it's the middle child．"There is，however，one thing that stops all conversation and prevents anyone from having attention："When the TV is on，"Lewis says，"dinner is a non-event．" 9．The writer's purpose in writing the text is toC． A．show the relationship between parents and children B．teach parents ways to keep order at the dinner table C．report on the findings of a study D．give information about family problems 10．Parents with large families ask fewer questions at dinner becauseB． A．they are busy serving food to their children B．they are busy keeping order at the dinner table C．they have to pay more attention to younger children D．they are tired out having prepared food for the whole family 11．By saying"Middle children are invisible"in paragraph 3，Lewis means that middle childrenB． A．have to help their parents to serve dinner B．get the least attention from the family C．are often kept away from the dinner table D．find it hard to keep up with other children 12．Lewis'research provides an answer to the questionB． A．why TV is important in family life B．why parents should keep good order C．why children in small families seem to be quieter D．why middle children seem to have more difficulties in life．
16．People have smoked cigarettes for a long time now．The tobacco used to make cigarettes was grown in what is now part of the United States．Christopher Columbus，who discovered America，saw the Indians smoking，and soon the dried leaves were transported （运输） to Europe where smoking began to catch on．In the late 1800s，the Turks （土耳其人） made cigarettes popular． Cigarettes smoke contains at least two harmful substances （物质），tar and nicotine．Tar，which forms as the tobacco bums，damages the lungs and therefore affects breathing．Nicotine，which is found in the leaves，causes the heart to beat faster and increases breathing rate． Smoking cigarettes is dangerous．The U．S．Public Health Service stated that cigarette smoking is the cause of lung cancers and several other deadly diseases．The U．S．government now requires that each package of cigarettes bear （带有） a special warning about the danger of smoking．
16．The expression"catch on"in the passage may meanC． A．start B．cost a lot C．become popular D．dangerous 17．Before Columbus discovered AmericaD． A．Europeans had smoked B．Nobody smoked in the world C．Nicotine was not in tobacco D．Europeans had never smoked 18．In the nineteenth century smoking became popular because of the people inB． A．India B．Turkey C．the U．S． D．British 19．Breathing is affected byD． A．nicotine B．Tar C．heat D．both A and B 20．Which of the following is Not right？B A．Smoking cigarettes is thought to be dangerous． B．The U．S．Public Health Service has found the cause of lung cancers and several other deadly diseases． C．Cigarette smoking is the cause of lung cancers and several other deadly diseases． D．The U．S．government wants smokers to know the danger of smoking．
