To study past human migrations in Europe, （the name of a specific cell organelle) DNA is widely used.

It's 8:00 am. James Butters gives 18-month-old Thomas his milk, then breakfast. After getting Thomas into his outdoor clothes, they head for the park to watch birds and play on the grass. With lunchtime drawing near, they're back home for an afternoon of drawing, playing with cars, maybe watching some children's programs.

James isn't Thomas' dad. He is a nanny (保姆)—a man nanny, obviously, interestingly termed a "manny"—specially trained and in his third nannying position. At 27, he cares for Thomas, and another boy of a similar age. "It's much freer than an office job," he says, "and you're getting to see children develop and grow. You become very close to them, for sure. I don't think I'm special or better than a woman nanny; everyone has their own method. But I'm unusual.

Friends laughed when I started studying nursery nursing. In my class, I was the only man among 70 women. Somehow, I made it," he said.

Although it's not yet common to find men in traditional (传统的) nannying courses, things are changing. In the United States, parents are employing young mannies, sometimes to care for babies, but more often as active role models to get junior away from the TV and the computer. From rollerblading (轮滑) friends to summer swimming mannies, these are the big brothers who are always willing to play, largely because they're paid for it.

It is catching on here in Britain, too. Earlier this year, Norland nanny college welcomed its first full-time man student, 19-year-old Peter Cummins in Wales. While some families find it difficult to accept the idea of a young man in a traditional nannying role, man nannies are increasingly popular.

Which of the following can be the best title for the text?

A．Changes in Tradition

B．A New Job for Men

C．Mannies and Women Nannies

D．Baby Boys and Their Mannies

The females of our closest primate relatives, the chimpanzees, are not exactly paragons of sexual probity. A recent DNA study of behavior. in the forest of Africa’s Ivory Coast showed that despite the hurrying of local males, the wily females were stealing off so often that half their offspring turn out to be fathered by outsiders. Of bonobos, perhaps the less said the better, at least in a family magazine. These "pygmy chimps", as they are also known, share 98% of our genes and a tendency to what Freud termed "polymorphous perversity". They will have sex with anyone, male of female as readily as we humans shake hands and apparently for the same purpose.

The interesting thing is that female promiscuity seems to be a reproductively advantageous trait, which may explain why it prevails in the animal world. The more males a female prairie dog mates with, for example, the more likely she is to conceive and the larger her litters. Angier reports on data, still disputed, that suggest human females are more likely to get pregnant for sex with an adulterous lover than from sex with their spouse.

So, to the extent that females relied on male help in raising a family, the smartest female reproductive strategy may have involved no less treachery than the male one: behave promiscuously, so you' 11 be sure to get pregnant, but pretend to be monogamous professing undying love -- so that at least one of the fellows will think the kids are his and possibly take an interest in them. Hey, it fooled the evolutionary psychologists!

Men fall for pretty faces, women fall for healthy portfolios? Here’s another object lesson sometimes drawn from the evolutionary allegory of Monica and Bill: men go for beautiful women, while women are attracted to power and money, even when it comes in a fat, gray-haired middle-bound millionaire husband, there are more cases like ex-playmate Anna Nicole Smith and her late, wheelchair-bound millionaire husband, there are like elementary school teacher Mary Letourneau and her 13-year-old boyfriend. But since men tend to accrue wealth and power as they age, it’s a bit odd, as zoologist Desmond Moils once noted, that baleness doesn't necessarily activate the feminine positive response. It may be smart for women to go for the billionaires and tribal big shots, but in practice their choices are often politically and economically irrational, if not self-destructive. For example, Juliet fell for a scion of the enemy clan. In rock-and-roll tradition and movies from The Wild One to Shakespeare in Love. It’s the penniless who makes the girls scream -- and did anyone see Titanic?

There is in fact a respectable evolutionary rationale for such "irrational" female choices. Women may want loyal, provider-type mates to help them raise their children. But if their sons are not attractive to other women -- and hence keep the lineage thriving -- it might help if dad is a heartbreaker himself. Unfortunately, though, physical attractiveness is net a re- liable guide to reproductive "fitness', as in health and wealth. Consider the peacock, its gorgeous tall renders it fairly vulnerable to predators, so any peahen with a concern for her sons' longevity should opt for a more modestly cute one.

According to the information given in the first paragraph, we can infer that ______.

A．chimps also live in a civilized community

B．human beings are just similar to the chimps

C．people understand chimps quite well

D．the chimps and people live in similar societies

T4 DNA连接酶(T4 DNA ligase)

A controversy erupted in the scientific community in early 1998 over the use of DNA (deoxyribonucleic acid) fingerprinting in criminal investigations. DNA fingerprinting was introduced in 1987 as a method to identify individuals based on a pattern seen in their DNA, the molecule of which genes are made. DNA is present in every cell of the body except red blood cells. DNA fingerprinting has been used successfully in various ways, such as to determine paternity (父亲的身份) where it is not clear who the father of a particular child is. However, it is in the area of criminal investigations that DNA fingerprinting has potentially powerful and controversial uses.

DNA fingerprinting and other DNA analysis techniques have revolutionized criminal investigations by giving investigators powerful new tools in the attempt to prove guilt, not just establish innocence. When used in criminal investigations, a DNA fingerprint pattern from a suspect is compared with a DNA fingerprint pattern obtained from such material as hairs or blood found at the scene of a crime. A match between the two DNA samples can be used as evidence to convict a suspect.

The controversy in 1998 stemmed from a report published in December 1991 by population geneticists Richard C. Lewontin of Harvard University in Cambridge, Mass, and Daniel L. Hartl of Washington University School of Medicine in St. Louis, Mo. Lewontin and Hartl called into question the methods to calculate how likely it is that a match between two DNA fingerprints might occur by chance alone. In particular, they argued that the current method Cannot properly determine the likelihood that two DNA samples will match because they came from the same individual rather than simply from two different individuals who are members of the same ethnic group. Lewontin and Hartl called for better surveys of DNA patterns.

In response to their criticisms, population geneticists Ranajit Chakraborty of the University of Texas in Dallas and Kenneth K. Kidd of Yale University in New Haven, Conn. , argued that enough data are already available to show that the methods currently being used are adequate. In January 1998, however, the Federal Bureau of investigation and laboratories that conduct DNA tests announced that they would collect additional DNA samples from various ethnic groups in an attempt to resolve some of these questions. And, in April, the National Academy of Sciences called for strict standards and system of accreditation (鉴定合格) for DNA testing laboratories.

Before DNA fingerprinting is used, suspects ______ .

A．would have to leave their fingerprints for further investigations

B．could easily escape conviction of guilt

C．would have to submit evidence for their innocence

D．could be convicted of guilt as well

听力原文： Six consecutive days of spring rain had created a raging river running by Nancy Brown's farm. As She tried to herd her cows to higher ground, she slipped and hit her head on a fallen tree think. The fall knocked her out for a moment or two. When she came to, (32) Lizzie, one of her oldest and favorite cows, was licking her face. The water was rising. Nancy got up and began walking slowly with Lizzie. The water was now waist high. It was quite hard to walk in the water. Nancy's pace got slower and slower. Finally, all she could do was to throw her arm around Lizzie's neck and try to hang on. About twenty minutes later, Lizzie managed to successfully pull herself and Nancy out of the raging water and onto a bit of high land, a small island now in the middle of acres of white water.

Even though it was about noon, the sky was so dark and the rain and lightning so bad that it took rescuers another two hours to discover Nancy. A helicopter lowered a paramedic, who attached Nancy to a life-support hoist. (33) They raised her into the helicopter and took her to the school gym, where the Red Cross had set up an emergency shelter.

When the flood finally subsided two days later, Nancy immediately went back to the "island". (34) To her great grief, Lizzie was gone. She was one of nineteen cows that Nancy lost. "I owe my life to her," said Nancy sobbingly.

(33)

A．She was a farmer.

B．She was a cow.

C．She was a rescuer.

D．She was a horse.