根据短文内容，从题中所给的A、B、C、D四个选项中选出最佳答案。

     If you like to check your smartphone from time to time, you are not alone. In fact, using apps（应用程序）has now become part of everyday life.

Changba

      Changba, which has been described as "the best mobile karaoke for sound", allows you to sing along to over 2,000 songs. You can also share your KTV recordings with friends on social media sites such as Weibo, Wechat, Qzone, etc. The app allows users to create a photo show to go with their songs and comment on other people's songs. Changba can even filter the sound. For example, it can make cat noises sound like a beautiful chorus(合唱).

Moment Cam

     Moment Cam brings you some of the most useful features a camera app can have, such as adjusting the flash(调整闪光灯）,continuous shots, adjusting the timer, and choosing different sizes for photo-sharing sites. But what sets the app apart from all the others is the choice of simple mini-buttons that you hardly notice are there.

Carrot

     Carrot, a to-do list app, is a task manager with a personality, When you succeed in finishing your tasks, for example, Carrot praises you with a message such as "Way to go. Soon you'll be completing other people's to-do lists".But if you fail to perform your tasks, Carrot might say, "I'm angered at your behavior." And it may change its background from white to black to show how angry it is. So, if you need an extra push to finish your tasks, give Carrot a try.

    Hi, everyone. I'm Tina. I think our life in 2060 will be different from our life at the moment. There will be many robots in my house. Because robots will be cheap. And these robots will help my family do many kinds of work every day. Every morning the clock-robot will ask me to get up. Then the clothing-robot will dress me quickly. Next the kitchen-robot will make breakfast for me. When I get out of the house with my schoolbag, a car-robot will wait for me. After I show it my school ID card, the car will go. And then the car-robot will check my homework. When we get to school, the car-robot will say to me "See you tomorrow, Tina. Good luck."

    In the morning, I will have three lessons with my classmates. We'll study on the Internet. We'll use the e-book. The teachers are all robots. They are in different sizes and they can answer any question about any subject. In the afternoon, we'll go to the science lab to have two classes in a new plane. After class, we'll play football with robots. My classmates and robots can all be my friends. Don't you think the life with robots in the future will be fantastic?

How honey is made

    The coffee shop Starbucks will give people a discount if they bring their own cups. It wants to cut down on the number of paper cups that are put in the rubbish bins. It is part of a two month experiment in cafes in England. Starbucks wants to reduce waste and recycle more, The president of Starbucks in the UK said, "We are very happy to increase recycling rates(比率)，and reusable cups are a key part of our waste reduction plan." Bosses will decide later if they will continue the discounts. People who bring their own cups will not get a discount on the cafe's cheaper filter coffee.

    The problem of paper cups has been in the news a lot. Around seven million cups are thrown away every day. Reporters say that some cafes lie about how many paper cups they recycle. The reporters say the cafes do not recycle as many cups as they say. Customers wrongly believe that a coffee shop is environmentally friendly. Less than one in 400 paper cups at coffee shops are recycled. A coffee drinker said she would bring her own cup. She said, "I am so sad that cafes recycle so little. I thought they were more responsible."

    It's every parent's worst nightmare: there's a fire in the house the alarms are beeping, but the children are sleeping on. Now scientists have found a better way to rouse slumbering youngsters. Researchers in the US have discovered that playing a child a recording of his mother's voice is about three times more likely to wake him up than a traditional alarm.

    Writing in the Journal of Pediatrics, Smith and colleagues report how they compared the effects of four different smoke alarms on 176 children aged between 5 and 12 years old, none of whom had hearing difficulties or were taking any medication that affected their sleep. While one alarm featured a high pitched beeps he sort of commonly found in households the other three featured the voice of the child's mother calling either the child's name, giving instructions such as: "Wake up! Leave the room or both. Each child slept in a lab-based room that resembled a real bedroom.

    The results show that vocal alarms appear to be more effective than high-pitched beeps. About 90% of children woke for a voice alarm compared with just over 53% for the traditional alarm

    "High pitched beeping alarms don't wake up children well at all under about 12 years of age." Said Dr Gary Smith, a co-author of the research from the Nationwide Children's hospital in Ohio, although he said at present it is not known why He said it was important to look at developing better alarms

    Prof Niamh Nic Daeid, director of the Leverhulme Research Centre for Forensic Science at the University of Dundee, said the research found a human voice combined with a low frequency pulsing tone was far more effective in waking up children than a traditional high-pitched alarm. She also noted that more work was needed to explore whether other familiar sounds, such as a dog barking, might also prove effective in rousing children.

    Which is the tallest mountain on the earth? The answer must come fast—MT Everest, at a height of 29,000 feet.

    But that is only on land. For, if you were to measure (测量) from the bottom (底部) of the ocean. The tallest mountain in the world will probably be Mauna Kea in Hawaii. It is more than 15,748 feet under the sea and another 13.779 feet above it.

    As US scientist Cindy Lee Dover points out that the seafloor is the largest and least known place on the earth. We know more about Mars (火星) and Venus (金星) and the back side of the moon than we know about the seafloor.

    Some people have travelled to the deep water of the ocean to try to find all kinds of unknown animals and plants living in the deep water. Even scientists know very little about them. Many of them perhaps do not even have names. Some of the names given by scientists to newly discovered (被发现) animals are really funny. Among them are the spaghetti worms (意大利面蠕虫), named as such it is found in a tangle (缠结), it is often difficult to make out where one ends and another begins! Just like spaghetti.