Nature has its own way of balancing itself out，but when we humans get involved，we tend to throw things out of control. Forests and oceans are natural carbon sinks that absorb carbon dioxide from the atmosphere, but since we’ve been pumping too much into the air, those sinks can’t keep up. Scientists at the Max Planck Institute for the Advancement of Science in Germany, led by biologist Tobias Erb，have figured out a way to supercharge plants to make them better at absorbing carbon dioxide, which could be a key defense against climate change.

Erb and his team figured out a way to make plants more efficient（效率高的）at absorbing carbon, so that they consumed more carbon in a shorter amount of time. “If you think about plants, they are efficient carbon dioxide -fixing filters, but they are not fast,” Erb said. “I think there is a chance to improve existing biology with synthetic（人造的）biology.”

Erb’s team identified 17 enzymes（酶）from nine different organisms, re-engineering three of them, which had enlarged carbon consumption. When those enzymes worked together as a team, they worked better at not only plants’ natural enzymes, but also themselves individually.

Existing enzymes in plants consume about 5 to 10 molecules（分子）of carbon dioxide per second. The team of enzymes that Erb used consumed 80 molecules per second.

So far, these enzymes have only been tested in test tubes in the lab, but the next step is real world testing where the enzymes would be introduced into plants to see if the same result occurs. If those tests show that plants really can be supercharged, we will have a new tool in the fight against climate change where not only do we protect the amazing carbon-absorbing forests we have, but we also apply these super plants or an artificial leaf technology using the enzymes into other fields.

【小题1】Why can't forests and oceans balance nature nowadays?

A．Oceans and forests are getting smaller.

B．We human beings give off too much carbon dioxide.

C．A large number of forests are cut down.

D．There are too many creatures in the world.

【小题2】Which is the key defense against climate change according to Erb and his team?

A．To increase the plants' ability and efficiency to absorb carbon dioxide.

B．To make oceans and forests absorb more carbon dioxide quickly.

C．To reduce humans' activities giving off too much carbon dioxide.

D．To increase the number of plants in the world.

【小题3】What can we conclude from the last paragraph?

A．The enzymes have proved useful in the real world.

B．Erb’s team are confident about the technology.

C．The enzymes only work in the lab.

D．The technology may have a bright future.

【小题4】This passage is intended to ____.

A．introduce a possible way to better plants’ ability to absorb carbon dioxide

B．call on people to pay more attention to the balance of nature

C．analyze the cause and result of climate change related to plants

D．explore the possibility of using plants to fight against climate change

A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.
“It’s extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.
They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it’s connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.
While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers’ fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.
Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”
【小题1】The difficulty the team of engineers met with while making the robotic fly was that __________.

A．they had no model in their mind

B．they did not have sufficient time

C．they had no ready-made components

D．they could not assemble the components

【小题2】It can be inferred from paragraphs 3 and 4 that the robotic fly __________.

A．consists of a flight device and a control system

B．can just fly in limited areas at the present time

C．can collect information from many sources

D．has been put into wide application

【小题3】Which of the following can be learned from the passage?

A．The robotic flyer is designed to learn about insects.

B．Animals are not allowed in biological experiments.

C．There used to be few ways to study how insects fly.

D．Wood’s design can replace animals in some experiments.

【小题4】Which of the following might be the best title of the passage?

A．Father of Robotic Fly

B．Inspiration from Engineering Science

C．Robotic Fly Imitates Real Life Insect

D．Harvard Breaks Through in Insect Study

   According to a study published last week in the journal Science，scientists have found a way to change a plant's genes（基因）in order to make it use sunlight more quickly. Someday，the results could increase the amount of food produced around the world.

By changing a plant's genes，the scientists were able to increase leaf growth on plants by 14-20 percent. Specifically，scientists changed the plant's protective（保护的）system. “Normally，this system is activated when a plant gets too much sunlight，”said scientist Krishna Niyogi，co-author of the study. “When the plant senses the light，it gets rid of extra energy and creates more leaves. When the plant is in the shade，the protective system is turned off. But the process is slow.”

Stephen Long is the lead author of the study. He compared a plant's protective system to light-adjusting glasses.“When a person wears the glasses outside during the day，the lenses（镜片）darken and lighten depending on how sunny it is. Plants do the same thing，”he said.“But in plants the adjustment can take anywhere from 10 minutes to an hour. This makes it hard for plants to get the right amount of sunlight needed to create food.”

The new study sped up the process. By changing the plant's genes，it's more quickly than normal to turn on and turn off the protective system. As a result，leaf growth on the plants scientists used in the study increased. Leaf growth on two plants increased by 20 percent, while leaf growth on a third plant increased by 14percent. Scientists conducted the study on tobacco plants. But they thought the genetic modification would produce the same results in corn or rice.

【小题1】What does the plant's protective system need to keep activated?

A．Mild shade.	B．Leaf growth.
C．Genetic changes.	D．Enough sunlight.

【小题2】What does the underlined word“modification”in Paragraph 4mean?

A．Development.	B．Decoration.
C．Change.	D．Copying.

【小题3】What can we infer from this text?

A．Changing how a plant uses sunlight could mean more food in the future.

B．When the plant is in the shade, its protective system is turned off slowly.

C．Too much sunlight will damage plants' protective system.

D．It is hard for plants to create food without enough sunlight.

   A new keyboard can tell whether you are its owner. The keyboard records information about the typing pattern（模式）and sends it to a computer program. The program then checks to see if the pattern matches the right user. If not, an alarm sounds, and the computer locks the typist out. It locks out everyone else, even if the person knows the password. What's more, this equipment needs no batteries. It collects all the energy it needs from your actions of typing. Besides, the keyboard is also self-cleaning and the keys are free of damage from water, oil and dirt.

The keys of the new keyboard are made of the same inexpensive plastic that might be found on any other standard keyboard. But instead of being smooth, the keys have millions of tiny plastic nanowires（纳米线）on their surface area, increasing the effective contact areas between the plastics and fingers. This guarantees that there's enough power to run the keyboard as someone types.

Liming Dai, a scientist, did not work on the new keyboard, but he thinks the design could be important in getting better performance from a variety of equipment. "It could also be applied to a touch screen, for example, "Dai says. " Then smart phones and notepads could collect energy from someone's actions of typing or drawing. "

"Future work might make the keyboard even more useful, "Dai adds. " A later design might build tiny capacitors onto the nanowires, "he suggests. Capacitors are little devices that temporarily store electric charge. Those might then be LEDs to light a keyboard in the dark.

Zhonglin Wang is a co-designer of the new keyboard. His team has built a working model of the keyboard. "If a company decides to fund（资助）its production, this keyboard could be in stores in as few as two years, "says Wang.

【小题1】How does the new keyboard tell whether you are its owner？

A．By matching the typing pattern to the right user.

B．By sending alarms to a computer program.

C．By checking the right user's passwords.

D．By just recording information about the typing pattern.

【小题2】Why are there many nanowires on the surfaces of the keys？

A．To keep the keyboard free of damage.

B．To improve the speed of typing.

C．To make the keys smooth.

D．To help produce power.

【小题3】What's Dai's attitude to the new keyboard？

A．Unconcerned.	B．Doubtful.
C．Positive.	D．Critical.

【小题4】What is the best title for the text？

A．A New Keyboard Made of Nanowires

B．A New Keyboard Entirely Owned by You

C．A New Keyboard's Future

D．A New Keyboard Powered by Typing

   Scientists are debating how to limit their newly-discovered power to change genetic structure. Scientists have already changed the genes of farm animals and agricultural plants to make them more productive or stronger. But now they can also change genes in wild animals and plants. These genes would continue into later generations. For example，it may be possible for scientists' to remove from existence the kind of mosquitoes that carry the Zika virus. They might also be able to permanently remove species of plants and animals that are destructive to other species.

In a report published last week，the U.S. National Academies of Sciences，Engineering and Medicine said it supports continuing research on this kind of gene control. But it warned that it is not possible to know what will happen when these changed plants and animals are released into the wild.

Sixteen biologists，ethicists（伦理学家）and policymakers are on a National Academy of Sciences（NAS）committee that is examining the issue. They say that there is value to the new technology. But，they say，there is not enough evidence to support the release of changed organisms（生物）from the laboratory into nature.

Many people would support stopping mosquitoes and rats from carrying diseases. But scientists say we must understand the possible scientific，ethical，legal and social results of such action before we decide whether to take it. Gene modification is spread through reproduction（繁殖）.Changed genes will continue to spread as long as an animal or plant continues to reproduce. They cannot be limited to a farm or kept within a country's borders. Scientists are wondering what may happen if a changed organism mates with another species. They are not yet sure how the changed genes would affect the other species. It is possible that those genes could harm those creatures or even lead to their disappearance from our planet.

【小题1】What possible advantage does gene control in wild animals and plants have?

A．Changing the Zika virus permanently.

B．Removing the destructive species forever.

C．Having changed genes in their next generations.

D．Making all the species more productive and stronger.

【小题2】Which of the following is NOT true according to the passage?

A．Scientists are not sure what exact results gene modification leads to.

B．Scientists won't change any genes before they make the final decision.

C．Gene modification has benefited some farm animals and agricultural plants.

D．Scientists have not applied gene modification to wild animals and plants in case of possible danger.

【小题3】As for genetically changed wild animals and plants, what are scientists worried about?

A．They may become weaker or die out.

B．They may be more productive.

C．They may cause damage to their living habitat.

D．Their genes may spread to later generations.

【小题4】What can be the best title for the passage?

A．Stop research on gene control

B．How to change genetic structure

C．Power and danger of gene control

D．Advantages of gene control in wild animals and plants