Shopping centers，stadiums and universities may soon have a new tool to help fight crime.

A California company called Knightscope says its robots can predict and prevent crime. Knightscope says the goal is to reduce crime by half in areas the robots guard.

William Santana Li is the chief executive officer of Knightscope. He says，"These robot security guards will change the world. Our planet has more than seven billion people on it. It's going to quickly get to nine billion people. The security equipment that we have globally is just not going to develop that fast. The company's Autonomous Data Machines can become the eyes and ears of law enforcement（执法）."

"You want them to be machines plus humans. Let. the machines do the heavy and sometimes dangerous work and let the humans do the strategic decision-making work，so it's always working all together."

The machines do not carry weapons but they have day and night video cameras which are able to turn 360 degrees and can also sense chemical and biological weapons.

Some people may become concerned about their privacy, especially in connection with the video recordings. Some people may worry that such recordings will appear on the Internet. Eugene Volokh, a law professor at the UCLA School of Law, says the machines have to be used in the right way and it will be interesting to see how state laws deal with this kind of video.

William Santana Li says there is a long waiting list for the robots in the US. Workers in the company are working overtime to meet the demands of the market. At least 25 other countries are also interested in these robot security guards.

   After years of research and tests, the hybrid car was developed and put on the market. It's an interesting and exciting new improvement in today's world as we look for better ways to protect the quality of the air we breathe and protect our natural resources.

The quality of our air is affected by many different things. But one of the largest sources of air pollution is the burning of fossil fuel such as coal and gasoline which is used to power a car's engine. The Environmental Protection Agency（EPA）has set national standards to help control the level of harmful pollutants sent off into the air, and the automobile industry has acted by producing the hybrid car that uses less gas and therefore causes less pollution.

A hybrid car is a combination of a regular car that runs on gasoline and an electric car that is battery-powered. Some people tend to think that since the hybrid car is partially electric, you have to plug it in to charge it. But that's not how it works. The 144 volt battery pack（电池组）is actually recharged through the energy that is produced when the car's brakes are used. This is referred to as "regenerative braking", because it generates electricity.

Although the hybrid car still runs on gasoline most of the time, this helps it use less gas than a regular car. When the driver stops at a traffic light, the engine automatically shuts off to save fuel. Then, as soon as the driver puts the car in gear and touches the gas pedal（踏板）, the engine starts backing up.

Have you ever ridden in a car with someone which ran out of gas？That probably wouldn't happen if you were riding in a hybrid car. It flashes a warning on its computer screen that says, "I am low on gas. "When it completely runs out, the warning reads, "YOU ARENOW OUT OF GAS！"Then the electric power supply starts to work to let the driver travel a few more miles to a gas station.

   Every pet owner loves his pet. There is no argument here.

But when we asked our readers whether they would clone their beloved animals，the responses（反应）were split almost down the middle. Of the 228 readers who answered it，108 would clone their beloved animals，111 would not and nine weighed each side without offering an opinion.

Clearly，from readers’responses，this is an issue that reaches deeply into both the joy and eventual sadness of owning a pet. It also shows people’s widely different expectations over the developing scientific procedure.

Most of the respondents who favored the idea strongly believed it would produce at least a close copy of the original；many felt the process would actually return an exact copy. Those on the other side，however，held little hope that cloning could truly recreate a pet；many simply didn’t wish to go against the natural law of life and death.

Both sides expressed equal love for their animals. More than a few respondents owned“the dog/cat in the world”.They thought of their pets as their“best friend”，“a member of the family”，“the light of their life”.They told moving stories of pets’ heroism，intelligence and selfless devotion.

Few wonder the loss is so disturbing（令人不安的）and the cloning so attractive.“People become very close to their animals，and the loss can be just as hard to bear as when a friend or family member dies，”says Gary A. Kowalski，author of Goodbye Friend：Healing Wisdom for Anyone Who Has Ever Lost a Pet. “For me，cloning feels like an attempt to turn death away... It’s understandable. Death is always painful. It’s difficult to deal with it. It’s hard to accept.”

But would cloning reduce the blow? This question seemed to be at the heart of this problem.

   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.

   Humans have been keeping animals as pets for tens of thousands of years, but Dr Jean-Loup Rault, an animal scientist at the University of Melbourne in Australia, believes new companions are coming: robot pets.

“Technology is moving very fast,” Rault told ABC News, “The Tamagotchi in the early 1990s was really the first robotic pet, and now Sony and other big companies have improved them a lot.”

This may not sit well with pet lovers. After all, who would choose a plastic toy over a lovely puppy? But Rault argues that the robotic kind has a lot going for it: “You don’t have to feed it, you don’t have to walk it, it won’t make a mess in your house, and you can go on a holiday without feeling guilty.” The technology also benefits those who are allergic to pets, short on space, or fearful of real animals.

It’s not clear whether robot pets can replace real ones. But studies do suggest that we can bond with these smart machines. People give their cars names and kids give their toy animals life stories. It’s the same with robots. When Sony stopped its repair service for its robot dog Aibo in March 2014, owners in Japan held funerals.

As an animal welfare researcher, Rault is concerned about how robotic pets could affect our attitudes towards live animals. “If we become used to a robotic companion that doesn’t need food, water or exercises, perhaps it will change how humans care about other living beings,” he said.

So are dogs and cats a thing of the past, as Rault predicts? For those who grew up with living and breathing pets, the mechanical kind might not do. But for our next generation who are in constant touch with smart technology, a future in which lovely pets needn’t have a heartbeat might not be a far-fetched dream.