5. Passage Thirty-ThreeWe all know that DNA has the ability to identify individuals but， because it is inherited， there are also regions of the DNA strand which can relate an individual to his or her family (immediate and extended)， tribal group and even an entire population.Molecular Genealogy (宗谱学)can use this unique identification provided by the genetic markers to link people together into family trees.Pedigrees (家谱)based on such genetic markers can mean a breakthrough for family trees where information is incomplete or missing due to adoption， illegitimacy or lack of records.There are many communities and populations which have lost precious records due to tragic events such as the fire in the Irish courts during Civil War in 1921 or American slaves for whom many records were never kept in the first place.The main objective of the Molecular Genealogy Research Group is to build a database containing over 100，000 DNA samples from individuals all over the world.These individuals will have provided a pedigree chart of at least four generations and a small blood sample.Once the database has enough samples to represent the world genetic make-up， it will eventually help in solving many issues regarding genealogies that could not be done by relying only on traditional written records.Theoretically， any individual will someday be able to trace his or her family origins through this database.In the meantime， as the database is being created， molecular genealogy can already verify possible or suspected relationships between individuals.“For example， if two men sharing the same last name believe that they are related， but no written record proves this relationship， we can verify this possibility by collecting a sample of DNA from both and looking for common markers (in this case we can look primarily at the Y chromosome (染色体)，” explains Ugo Perego， a member of the BYU Molecular Genealogy research team.Which of the following CANNOT be inferred from the passage?

1.The Words of his old teacher left a ()impression on his mind.He is still influenced by them.

A. 　long

B. 　lively

C. 　lasting

D. 　liberal

14.When people become unemployed， it is ()which is often worse than lack of wages.

A. 　laziness

B. 　poverty

C. 　idleness

D. 　inability

3. Passage ThirteenTrees are useful to man in three important ways: they provide him with wood and other products; they give him shade; and they help to prevent droughts and floods.Unfortunately， in many parts of the world， man has not realized that the third of these services is the most important.In his eagerness to make money from trees， he has cut them down in large numbers， only to find that without them he has lost the best friends he had.And besides， he is usually too careless to plant and look after new trees.So the forests slowly disappear.This does not only mean that man will have fewer trees.The results are even more serious: for where there are trees， their roots break up soil——allowing the rain to sink in——and also bind the soil， thus preventing it from being washed away easily; but where there are no trees， the rain falls on hard ground and flows away， causing floods and carrying away the rich topsoil.When all the topsoil is gone， nothing remains but worthless desert.Two thousand years ago a rich and powerful country cut down its trees to build warships， with which to gain itself an empire.It set up the empire but， without its trees， its soil became poor and it grew weak.When the empire fell into pieces， there is nothing left except floods and starvation.Why did the country mentioned in the passage suffer from floods and starvation?

6.In no country ()Britain， it has been said， can one experience four seasons in the course of a single day.

A. 　other than

B. 　more than

C. 　better than

D. 　rather than

43.The government has put forward a new policy aimed at preserving the city’s important historic sites.

4. Passage ElevenDoctors say anger can be an extremely damaging emotion， unless you learn how to deal with it.They warn that anger can lead to heart disease， stomach problems， headaches， emotional problems and breast cancer.Anger is a normal emotion that we all feel from time to time.Some people express anger openly in a calm and reasonable way.Others burst with anger， screaming and yelling.But still others keep their anger inside.They cannot or will not express it.This is called (repressing)anger.For years some doctors claim that both repressing and expressing anger can be dangerous.They say that in both situations the brain of an angry person releases the same hormones (荷尔蒙).They spend the heart rate， raise blood pressure or sugar level in the blood.As a result， the angry person feels excited and is ready to react.The violent reaction may lead to high blood pressure.However， some other doctors argue that repressing anger is more dangerous to a person’s health than expressing it.They believe that those who keep their anger inside may face a greater danger of heart disease.Most doctors agree that it is important to learn how to deal with anger.They say the first step is to admit that you are angry and recognize the real cause of the anger， then decide if the cause is serious enough to get angry about.If so， you should not express your anger immediately and try to wait until your anger has cooled down， so that you are able to express yourself calmly and reasonably.They also believe that a good way to deal with anger is to find humor in the situation that has made you angry.After all， it is much healthier to laugh than to get angry.What is the best title for this passage?

45.She gave us food and clothes and asked for nothing in return， which made us very grateful.

42.We should take an active part in community service， which can enrich our life.

6、The pollution of groundwater by nitrates(硝酸盐)is of concern to public health authorities and environmental organizations because high nitrate concentration(高硝酸含量)s in drinking water can cause methaemoglobinaemia(高铁血红蛋白血)in infants.Another environmental problem associated with high nitrate concentration in groundwater is eutrophication(富营养化)of receiving waters(供水).Virtually all decisions about the control of nitrate pollution of ground water are made in the face of uncertainties that frustrate(阻止，挫败)efforts to guarantee the desired results.The decisions also have to be made in an adversarial(意见相左，敌对不可调和的)environment in which the goals of society and those of the agricultural sector(农业部门)are often different.

34. Questions 31 to 35 are based on the following passage.The United States is facing a housing crisis: Affordable housing is inadequate， while luxury homes abound (充裕)， and homelessness remains a persistent problem.Despite this， popular culture and the housing industry market happiness as living with both more space and more amenities (便利设施).Big houses are advertized as a reward for hard work and diligence， turning housing from a basic necessity into a luxury.This is reflected in our homes.The average single-family home built in the United States before 1970 was less than 1，500 square feet in size.By 2016， the average size of a new， single-family home was 2，422 square feet.What’s more， homes built in the 2000s were more likely than earlier models to have more of all types of spaces: bedrooms， bathrooms， living rooms， dining rooms， recreation rooms and garages.There are consequences of living big.As middle-class houses have grown larger， two things have happened.First， large houses take time to maintain， so cleaners and other low-wage service workers are required to keep these houses in order.Second， once-public spaces， where people from diverse backgrounds used to come together， have increasingly become privatized， leading to a reduction in the number of public facilities available to all， and a reduced quality of life for many.Take swimming pools.While in 1950， only 2，500 U.S.families owned pools， by 1999 this number was 4 million.At the same time， public municipal pools were often closed， leaving low-income people nowhere to swim.The trend for bigger housing thus poses ethical questions.Should Americans accept a system in which the middle and upper classes enjoy a luxurious lifestyle， using the low-wage labor of others? Are we willing to accept a system in which an increase in amenities purchased by the affluent means a reduction in amenities for the poor?I believe neither is acceptable.We must change the way we think: living well does not need to mean having more private spaces; instead， it could mean having more public spaces.A better goal than building bigger houses for some is to create more publicly accessible spaces and amenities for all.What kind of social system does the author think is unacceptable?

A. 　One in which the wealthy exploit the low-wage laborers building their houses.

B. 　One in which the rich purchase amenities at an increasingly unjustifiable price.

C. 　One in which the upper classes deprive the lower classes of affordable housing.

D. 　One in which the affluent enjoy a more comfortable life at the expense of the poor.