Which country is the biggest consumer of petroleum？A．The United States.B．Russia.C．Norway.D

A．reliable

B．trustworthy

C．dependent

D．grand

Why do boys and girls in co-education have no illusion about each other？

A．They live together and know each other too well.

B．Years of living together at school dismiss such illusions.

C．Co-education encourages them to have an healthy attitude toward life.

D．They are familiar with each other's problems.

We can infer from the passage that some parents send their children to receive education other than co-education, because______.

A．Parents worry about their children's safety

B．Parents are afraid of their children's being involved in love affairs at an early age

C．Parents think that these schools are perfect

D．Parents hope that their children can acquire as much knowledge as possible

In the angry debate over how much of IQ comes from the genes that children inherit from parents and how much comes from experiences, one little fact gets overlooked: no one has identified any genes (other than those that cause retardation) that affect intelligence. So researchers led by Robert Plomin of London's Institute of Psychiatry decided to look for some:

Plomin's colleagues drew blood from two groups of 51 children each. They are all White living in six counties around Cleveland. In one group, the average IQ is 136. In the other group, the average IQ is 103. Isolating the blood cells, the researchers then examined each child's chromosome 6 (One of the 23 human chromosomes). Of the 37 land marks on chromosome 6 that the researchers looked for, one jumped out: a form. of gene called IGF2R occurred in twice as many children in high IQ group as in the average growth—32 percent versus 16 percent. The study concludes that it is this form. of the IGF2R gene, called allele 5, that contributes to intelligence.

Plomin cautions that "This is not a genius gene. It is one of many". (About half the differences in intelligence between one person and another are thought to reflect different genes, and half reflect different life experiences.)The gene accounts for no more than four extra IQ points. And it is neither necessary nor sufficient for high IQ: 23 percent of the average-IQ kids did have it, but 54 percent of genius kids did not.

The smart gene is known by the snappy name "insulin like growth factor 2 receptor" (IGH2R to its fun). It lets hormones like one similar to insulin dock with cells. Although a gene involved with insulin is not the most obvious candidate for an IQ gene, new evidence suggests it might indeed play the role. Sometimes when s hormone docks with the cell, it makes the cell grow; sometimes it makes the cell commit suicide. Both responses could choreograph the development of the brain. Scientists at the National Institutes of Health find that insulin can stimulate nerves to grow. And in rat brains, regions involved in learning and memory are chock full of insulin receptors.

Even though this supports the idea that IGF2R can affect the brain and hence intelligence, some geneticists see major problems with the IQ-gene study. One is the possibility that Plomin's group fell for what's called the chopsticks fallacy. Geneticists might think they've found a gene for chopsticks dexterity, but all they've really found is a gene more common in Asians than, say, Africans. Similarly, Plomin's IQ gene might simply be one that is more common in groups that emphasize academic achievement. "What if the gene they've found reflects ethnicity？" asks geneticist Andrew Feinberg of Johns Hopkins University. "I would take these findings with a whole box of salt".

As for how much of IQ comes from the genes and how much come from experiences,______.

A．scientists have reached an agreement

B．scientists' opinions vary

C．no genes have ever been identified

D．scientists have found many smart genes

A healthy person has______. chromosomes all together.

A．6

B．23

C．37

D．46

It is found that insulin______.

A．is IQ gene

B．has nothing to do with IQ gene

C．stimulates nerves to grow

D．is decisive to the development of intelligence

Some geneticists don't accept the IGF2R gene-study because______.

A．the subjects are not worldwide

B．the subjects are from the groups that emphasize academic achievement

C．the findings have not been replicated by other researchers

D．both A and B

The phrase "with a whole box of salt" in the last paragraph means______.

A．skeptically

B．willingly

C．publicly

D．undoubtedly

E-mail—can't live with it, can't live without it. Con artists and real artists, advertisers and freedom fighters, lovers and sworn enemies-they've all flocked to email as they would to any new medium of expression. E-mail is convenient, saves time, brings us closer to one another, helps us manage our ever-more-complex lives. Books are written, campaigns conducted; crimes committed-all via e-mail. But it is also inconvenient, wastes our time, isolates us in front of our computers and introduces more complexity into our already too-harried lives. To skeptics, E-mails just the latest chapter in the evolving history of human communication. A snooping husband now discovers his wife's affair by reading her private e-mail—but he could have uncovered the same sin by finding letters a generation ago.

Yet E-mail—and all online communication—is in fact something truly different; it captures the essence of life at the close of the 20th century with an authority that few other products of digital technology can claim. Does the pace of life seam ever faster？ E-mail simultaneously allows us to cope with that acceleration and contributes to it. Are our attention spans shriveling under barrages of new, improved forms of stimulation？ The quick and dirty E-mail is made to order for those whose ability to concentrate is measured in nanoseconds. If we accept that the creation of the globe spanning Internet is one of the most important technological innovations of the last half of this century, then we must give E-mail—the living embodiment of human connections across the Net—pride of place. The way we interact with each other is changing; E-mail is both catalyst and the instrument of that change.

The scope of the phenomenon is mind-boggling. Worldwide, 225 million people can spend and receive E-mail. Forget about the Web or e-commerce or even online pornography: E-mail is the Internet's true killer app—the software application that we simply must have, even if it means buying a $2,000 computer and plunking down $20 a month to America Online. According to Donna Hoffman, a professor of marketing at Vanderbilt University, one survey after another finds that when online users are asked what they do on the Net, "E-mail is always No. 1."

Oddly enough, no one planned it, and one predicted it. When research scientists first began cooking up the Internet's predecessor, the Arpanet, in 1968, their primary goal was to enable disparate computing centers to share resources. "But it didn't take very long before they discovered that the most important thing was the ability to send mail around, which they had not anticipated at all", says Eric Auman, chief technical officer of Sendmail, Inc.

What does the first sentence of the passage mean？

A．E-mail brings convenience as well as inconvenience.

B．E-mail complicates our lives.

C．E-mail links us to others more closely, but at the same time, it isolates us as well.

D．E-mail draws crowds of people who can't live with or without it.

Despite the vast popularity of E-mail, there are still people who don't think much of it because______.

A．they think as the latest invention in communication technology it hasn't reach its best

B．they think it may be replaced by newer communication technology it does the older ways of communication

C．they think it is no better than the older ways of communication

D．they think its invention is one inevitable step in human evolution just like that of the older ways of communication