When you're not at home, many worries may start to crowd your mind. Did I turn the coffee maker off? Did I lock the door? Are the kids doing their homework or watching television? With a smart home, you can quiet all of these worries.

　　　A smart home is a home with a communication network. This network connects devices(装置),such as lights and TV sets, and allows them to be controlled from far away through electrical wiring, mobile phone communication or WiFi over the internet.

　　　More and more people may start to consider owning a smart home, because it makes life much more convenient. It can help keep your room at a certain temperature. It can record what happens inside the home and send the video to your phone. When you are on vacation abroad, you can use a smart home controller to switch on or off the electricity when necessary. Some smart homes can receive a visitor, allowing him to come in and offering him a drink. They can even feed the cat and water the plants.

　　　Besides, smart homes are easy to fix. Most smart home technology and devices are wireless and can be set up with a minimum of tools, using only the guiding information. When a problem appears, you can deal with it yourself without paying a professional.

　　　However, for home-users, the smart home technology is far from perfect. It can be rather expensive to own the technology and the devices. Also, because the smart home system(系统)allow its owner to get home information from anywhere, it leaves the home easy to be attacked by hackers(黑客),who may secretly use or change the information in the system.

　　　Now, many scientists are excited at the future of smart home technology. Imagine being able to get fashion advice from your mirror, or receive food shopping suggestions from your refrigerator. While there are others who worry that those smart devices will make people lazier and lonelier. Whatever it is, one thing is for sure—smart home technology will change the way we live and work.

阅读下面四篇短文，从每题所给的A、B、C、D四个选项中选出最佳选项。

C

    Indian scientists have designed a new device that they hope will solve one of the biggest problems with the use of solar energy. They call the device a solar tree. Solar trees have metal “branches” which are just from a tall pole at different levels. Each branch holds a solar panel*. These panels have large metal boards that collect energy from the sun and turn it into electricity.

    Daljit Singh Bedi is the main scientist at the Council of Scientific and Industrial Research in India. Bedi says the shape of the solar trees makes it possible to fit more solar panels in a space than traditional systems do. This means less land would be needed to produce solar energy. “It takes about four square meters of space to produce energy which may need 400 square meters of space,” he says.

     Scientists believe the energy a solar tree collects will be enough to power five homes. The solar tree will make it easier to provide solar energy for homes in cities. The trees will also take less space from farmers in rural areas. Bedi says solar trees will collect more energy than normal solar panels on the tops of buildings. “This design makes the solar panels exposed more towards the sun,” he says. “And that way people are able to use 10 to 15 percent more energy.”

    India has promised to reduce its greenhouse gas production. The country's promise depends heavily on increasing solar energy. The cost of solar panels has gone down in recent years. This has increased the possibility of applying solar trees in India.

    Amit Kumar is the senior director of the Energy and Resources Institute in New Delhi. He says gaining access to land takes time and increases costs. He adds that it is still not clear how useful these new developments in solar power technology are. “Only when we put those trees on a large scale will we be able to get that answer,” he says.

    One of the hottest places on Earth is Death Valley. It's a desert valley in North America. The animals in Death Valley don't use technology to keep cool. They have special abilities that help them live there.

    During the day in Death Valley, it gets hotter than 100°F. The kangaroo rat rests all day in a hole in the ground. It covers the hole with grass to keep out the heat. The kangaroo rat comes out at night when it is cooler. This little rat is also very good at saving water. It gets all the water it needs from the food it eats. The Sun makes the desert sand very hot. One snake, called the sidewinder, can solve this problem. When it travels, the sidewinder bends (弯曲) its body into a "W" shape. Then it uses the bottom parts of the "W" like legs and walks sideways (向一侧). That way it touches only a little of the sand at a time, so the hot sand doesn't bum the snake. This strange way of moving is how the sidewinder got its name.

    A lot of water in the desert is too salty for most animals to drink. One kind of fish, the desert pupfish, can live in these salty water because it can drink the salt water.

    What will our homes be like in the future? Here are some predictions:

    Want to take a shower when you get home? You'll be able to let your smart water heater(热水器) to start heating up when you're on your way home..

    Did I turn off the oven? Did I close the window? Everyone may have a moment like that. But in the future, your home will check these for you.

    In your home of the future, all of your devices (设备) can work together to make your life more comfortable. When you turn on the lights in the morning, your windows will open at the sometime. The lights will slowly turn off by themselves after the sun appears.

    Your home may have dangers. The hackers (黑客)could open your door and cause a mess at your home through your phone or other devices. Your home will tell you about it, but you can't arrive in time. So people will have to be careful of their personal information.