Why did humans evolve to walk upright? Perhaps because it’s just plain easier. Make that “energetically less costly”, scientifically speaking.

Bipedalism—walking on two feet, is one of the defining characteristics of being humans, and scientists have debated for years how it came about. In the latest attempt to find an explanation, researchers trained five chimps(黑猩猩)to walk on a treadmill(跑步机)while wearing masks that allowed measurement of their oxygen consumption. The chimps were measured both while walking upright and while moving on their legs and knuckles(膝关节).That measurement of the energy needed to move around was compared with similar tests on humans and the results are published in this week’s online edition of “Proceedings of the National Academy of Sciences”.

It turns out that humans walking on two legs use only one-quarter of the energy that chimps use while knucklewalking on four limbs(肢).And the chimps, on average, use as much energy using two legs as they did when they used all four limbs.

However, there were differences among chimps in how much energy they used, and this difference corresponded to their different manner of walking and anatomy(解剖构造).One of the chimps used less energy on two legs, one used about the same and the others used more, said David Raichlen, assistant professor of anthropology at the University of Arizona.

“What we were surprised at was the variation(变异) ”, he said in a telephone interview. Interview. “That was pretty exciting, because when you talk about how evolution works, variation is the bottom line, without variation there is no evolution.”

Walking on two legs freed our arms, opening the door to drive the world, said Raichlen. “We think about the evolution of bipedalism as one of first events that led hominids(原始人)down the path to being humans.”

The research was supported by the National Science Foundation and the L.S.B.Leakey Foundation.

The underlined word “Bipedalism” in Paragraph 2 probably means____.

A．moving sideways              B．walking upright

C．walking on four legs            D．running fast

We can infer from the passage that____.

A．scientists have no idea on how humans’ walking on two legs came about

B．scientists have had different views on why chimps walk on four legs

C．scientists have had different views on how humans’ walking on two legs vame about

D．scientists have had similar views on how humans’ walking on two legs came about

What is Paragraph 4 mainly about?

A．How chimps saved energy.

B．Why chimps didn't walk on two legs.

C．David Raichlen studied chimps.

D．Different chimps consumed different energy.

According to the passage, humans walk upright in order to____.

A．conserve energy                  B．differ from other animals

C．free their brains                  D．strengthen their legs

By 2050
Futurologists predict that life will probably be very different in 2050.
TV channels will have disappeared. Instead, people will choose a program from a “menu” and a computer will send the program directly to the television. Today, we can use the World Wide Web to read newspaper stories and see pictures on a computer thousands of kilometers away. By 2050, music, films, programs, newspapers, and books will come to us by computer.
Cars will run on new, clean fuels and they will go very fast. Cars will have computers to control the speed and there won’t be any accidents. Today, many cars have computers that tell drivers exactly where they are. By 2050, the computer will control the car and drive it to your destination. Space planes will take people halfway around the world in 2 hours. Today, the United States Space Shuttle can go into space and land on Earth again. By 2050, space planes will fly all over the world and people will fly from Los Angeles to Tokyo in just 2 hours.
Robots will have replaced people in factories. Many factories already use robots. Big companies prefer robots—they don’t ask for pay rises or go on strike, and they work 24 hours a day. By 2050, we will see robots everywhere—in factories, schools, offices, hospitals, shops and homes.
Medical technology will have conquered many diseases. Today, there is equipment that connects directly to the brain to help people hear. By 2050, we will be able to help blind and deaf people to see and hear again.
Scientist will have discovered how to control genes（基因）. Scientists have already produced clones(克隆) of animals. By 2050, scientists will be able to produce clones of people, and decide how they look, how they behave and how clever they are. Scientists will be able to do these things, but should they?
【小题1】
According to the passage, the following can be realized today EXCEPT __________.

By 2050

Futurologists（未来学家）predict that life will probably be very different in 2050.

TV channels（频道）will have disappeared. Instead, people will choose a program from a “menu” and a computer will send the program directly to the television. Today, we can use the World Wide Web to read newspaper stories and see pictures on a computer thousands of kilometers away. By 2050, music, films, programs, newspapers, and books will come to us by computer.

Cars will run on new, clean fuels and they will go very fast. Cars will have computers to control the speed and there won’t be any accidents. Today, many cars have computers that tell drivers exactly where they are. By 2050, the computer will control the car and drive it to your destination. Space planes will take people halfway around the world in 2 hours. Today, the United States Space Shuttle can go into space and land on Earth again. By 2050, space planes will fly all over the world and people will fly from Los Angeles to Tokyo in just 2 hours.

Robots will have replaced people in factories. Many factories already use robots. Big computers prefer robots—they don’t ask for pay rises or go on strike, and they work 24 hours a day. By 2050, we will see robots everywhere—in factories, schools, offices, hospitals, shops and homes.

Medical technology will have conquered many diseases. Today, there are devices（设备）that connect directly to the brain to help people hear. By 2050, we will be able to help blind and deaf people to see and hear again.

Scientist will have discovered how to control genes（基因）. Scientists have already produced clones（克隆）of animals. By 2050, scientists will be able to produce clones of people, and decide how they look, how they behave and how clever they are. Scientists will be able to do these things, but should they?

1.According to the passage, the following can be realized today EXCEPT __________.

2.We can learn from the passage that some big companies prefer robots to human workers, because human workers __________.

3.From Paragraph 5 we can infer that __________.

4.What is the author’s attitude towards the cloning technology?

By 2050
Futurologists（未来学家）predict that life will probably be very different in 2050.
TV channels（频道）will have disappeared. Instead, people will choose a program from a “menu” and a computer will send the program directly to the television. Today, we can use the World Wide Web to read newspaper stories and see pictures on a computer thousands of kilometers away. By 2050, music, films, programs, newspapers, and books will come to us by computer.
Cars will run on new, clean fuels and they will go very fast. Cars will have computers to control the speed and there won’t be any accidents. Today, many cars have computers that tell drivers exactly where they are. By 2050, the computer will control the car and drive it to your destination. Space planes will take people halfway around the world in 2 hours. Today, the United States Space Shuttle can go into space and land on Earth again. By 2050, space planes will fly all over the world and people will fly from Los Angeles to Tokyo in just 2 hours.
Robots will have replaced people in factories. Many factories already use robots. Big computers prefer robots—they don’t ask for pay rises or go on strike, and they work 24 hours a day. By 2050, we will see robots everywhere—in factories, schools, offices, hospitals, shops and homes.
Medical technology will have conquered many diseases. Today, there are devices（设备）that connect directly to the brain to help people hear. By 2050, we will be able to help blind and deaf people to see and hear again.
Scientist will have discovered how to control genes（基因）. Scientists have already produced clones（克隆）of animals. By 2050, scientists will be able to produce clones of people, and decide how they look, how they behave and how clever they are. Scientists will be able to do these things, but should they?
【小题1】According to the passage, the following can be realized today EXCEPT __________.

We keep reading that TV is bad for you. If this is true, how come the current generation of TV-addicted kids is much smarter than we are? In my home, the only people who can work the remote control are the children.
Perhaps TV does educate you. For example, you learn a useful medical fact: A person who has been shot always has time to speak an incomplete sentence before he dies. “The killer was…” (dies)
But I guess the biggest things we learn from TV can be regarded as “Life Skills”. Bad things only happen on dark and stormy nights. Emotional breakdowns cause people to wander in the heavy rain without umbrellas. And contrary to what scientists say, the crack(霹雳) of lightning and the accompanying flash happen at exactly the same time, wherever you are.
I’ve even acquired useful geographical facts from science-fiction shows: Aliens speak English no matter which planet they come from.
Making use of what we learn from TV can improve our security. Consider these truths. If you are ever attacked by 20 bad guys, don’t worry about being outnumbered. The criminals will hang back and take turns to approach you in ones and twos just so you can conveniently defeat them all. Bad guys who are completely covered in black clothes always remove their black masks to reveal that they are in fact, aha, women.
TV also teaches us important information about escaping from danger. Watch and learn. (1) If anyone is running after you down a passage, you will find that boxes have been conveniently placed near all the walls you need to jump over. (2) If you are tall and handsome, you can run from any number of armed criminals, and every shot will miss you.
Be warned, however. If your name card says “henchman” (帮凶) and you are part of a group of plain-looking people trying to catch a handsome individual, a single shot will kill you. But don’t be anxious: TV also delivers useful information for bad guys. All cars are inflammable (易燃的) and have amazing shock absorbers that enable them to fly into the air and land without damage — except police cars.
TV even teaches us about TV. Whenever anyone turns on a TV, it shows a news flash about someone they know. They then turn the box off immediately after that news item.
【小题1】By saying “A person who has been shot always has time to speak an incomplete sentence
before he dies” (Paragraph 2), the writer shows his________.

A．bad things cause people to break down in the rain

B．bad things never happen on dark and stormy nights

C．people with emotional problems like to walk in the rain without umbrellas

D．the crack of lightning and the accompanying flash don’t happen at the same time