C

    After a long day's study at school, you are very tired. So after school you go home to relax. When you get home, a robot greets you. He's happy to see you and helps you take your school things to your room. He listens to you talk about your school life and tells you a new joke. And he tells you to call your cousin and to say happy birthday. And then he helps you with your homework.

    This is your future, and the robot's name is NAO. NAO has a small body, big eyes and a large head. He can walk and dance. He listens and talks, and he even learns and thinks for himself. His creators(创造者) predict that the robot will be in people's homes before 2040.

    This $16,000 robot knows who you are. NAO can even express emotions(表达情感). He is a self-guided robot. A self-guided robot can sense(感觉), think and act. Other robots might do two out of the three. For example, a robot might sense things using cameras and think using computers, but with no arms, he can't act. Another robot can move and sense things, but he can't think for himself. These aren't self-guided robots. But NAO can do them all.

阅读下面短文，从A、B、C、D四个选项中选出最佳选项。

    Almost everybody in America will spend a part of his or her life behind a shopping cart. They will, in a lifetime, push the shopping carts many miles, but few will know—or even think to ask—who it was that invented them.

    Sylvan N. Goldman invented the shopping cart in 1937. At that time he was in the supermarket business. Every day he would see shoppers lugging groceries around in baskets they had to carry.

    One day Goldman suddenly had the idea of putting baskets on wheels. To create the first shopping cart, Goldman used folding chairs. He out one basket on the seat, and he raised the chair by putting wheels under the legs. The wheeled baskets would make shopping much easier for his customers, and would help to attract more business.

On June 4, 1937, Goldman's first carts were ready for use in his market. He was terribly excited on the morning of that day as customers began arriving. He couldn't wait to see them using his invention. However, Goldman was disappointed. Most shoppers gave the carts a long look, but hardly anybody would give them a try. After a while, Goldman decided to ask customers why they weren't using his carts.

    "Don't you think this arm is strong enough to carry a shopping basket?" one shopper replied.

    Goldman wasn't beaten yet. He knew his carts would be a great success if only he could persuade people to give them a try. To this end, Goldman hired a group of people to push carts around his market and pretend they were shopping! Seeing this, the real customers gradually began copying the phony customers.

As Goldman had hoped, the carts were soon attracting larger and larger numbers of customers to his market. Not only did more people come—those who came bought more. With larger, easier-to-handle baskets, customers unconsciously bought a greater number of items than before.

    Today's shopping carts are five times larger than Goldman's original model. Perhaps that's one reason Americans today spend more than five times as much money on food each year as they did before 1937—before the coming of the shopping cart.

    In the Charles F. Johnson Elementary School in New York, there is a special radio. It gives people warnings about bad weather.

    One day, there came a sound from the radio. This sound brought the piece of news: a heavy storm was coming. William Tomic, principal(校长) of the school, asked teachers to bring children indoors and put them in a safe place at once.

    Minutes later, the storm came. However, because of the warning of the radio and the quick work of the principal, no one was hurt.

    "The radio really did work very well.(A)(我们对它的工作感到很满意), "William Tomic said. "The parents were happy as well."

    The U. S. government hopes there will be more such successful stories. It plans to give this kind of radio to all 97, 000 public schools in the country.

    Every year, more than 10, 000 big thunderstorms, 2, 500 floods, 1, 000 tornadoes(龙卷风) and some hurricanes(飓风) take place in the U. S., so the warning radios are very useful. They not only give people warnings about bad weather, but also give warnings about other dangerous  things.

    April will bring a new product– the Apple Watch into the market. Last week, the watch was firstly introduced by Tim Cook, Apple's CEO. The price of the watch is from $349 to $1,099, depending on its size and whether it is a sports or regular one. Apple engineers and designers have put in a lot of thought and hard work into creating this small screen on your wrist. The sensor(传感器)on the screen not only finds your finger, but also knows the difference between when you are tapping(轻触), and when you are pressing harder.

    The watch also has haptic feedback(触觉反馈). You can send personal messages to your friend —such as drawing a star or a special sign with your fingers, or tapping the watch, say 3 times, and your friend will receive those taps on their wrist.

    Besides telling the time, the watch will use 'Bluetooth' to connect with your iPhone and show calls or text messages that come in.

    According to Tim Cook, the watch may open up a whole new area of applications（应用） that we had never thought of. Some car factories like BMW have developed an app that allows its car owners to open their cars with the watch. A 'Hotels' app may allow you to open the door to your hotel room without worrying about losing the smart-card. And finally, even at the airport—passengers may be able to simply wave their wrist to check into their flight.

    The biggest use of the watch, however, is as your personal fitness coach. The watch can show your pulse (heartbeat) using a sensor at the bottom of the watch. It also has the same sensor as your iPhone, so it knows when you are moving, and also how much you are walking or running. It will remind you if you have been sitting for too long without taking exercise.

    Technology is everywhere. We see it any place we go and, in fact, almost all of us carry some piece of technology with us every time we leave the house. What I always forget, though, is just how useful and powerful technology can be when we want to help others.

    There is not a single room in my house that does not have some electronic devices （设备）lying around in it. Whenever I am at home, I am almost always using at least one electronic device. If you walked into my living room on any given day, you would find that, first, I have the television on. At the same time, I usually have my laptop resting on my knee, or I will be using my mobile phone. Even when I'm not at home I am always using my phone, and at work or in cafés, I sit down and connect to the local wireless network on my laptop.

    I must say that I waste a lot of time on the computer and the time I spend on it could be much better spent if I were to take up a little online volunteering.

    The technology we carry about everywhere can have a great power to do good for the world and to help others and recently I discovered just how much online volunteering there is to do in the world. From using your language skills to do translations, to developing and managing projects and helping with IT work, there is so much that so many people can do to help people in their own countries and across the world. The United Nations, in fact, has a huge page with "Volunteers Recruited" on its website.

    This work can support the poor and help charities who cannot pay for staff members. Many organizations only require you to work an hour a week﹣some even less. And the support provided by online volunteers can really help make a difference to those in need.