阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    A recent announcement by scientists that they have successfully cloned the first human embryo(胚胎) has caused much debate and has shocked many people around the world. On the one hand, some scientists point out that if you clone an embryo, you can produce valuable tissues(组织) and organs that could be used to save human lives. On the other hand, many people, including some scientists, disagree and fear that if mankind interferes with (干涉) nature in this way, they may be on their way to producing a real-life Frankenstein's monster.

Cloning is producing an exact copy of a plant or an animal using its cells. The first mammal to be cloned successfully from an adult cell was Dolly—the sheep. She was born in 1996 and died in early 2003, at a much younger age than normal. When she was born, many people were angry because they thought cloning would create more diseases in the animal world. However, in general the scientists were praised for their wonderful scientific breakthrough.

    The Scottish scientist who created Dolly, Ian Wilmut, is shocked that some scientists are now considering cloning human beings. Although he researches cloning, he has never thought of creating copies of humans. Instead, he thinks the scientists should concentrate on creating new tissues and organs that could eventually be used to cure diseases like cancer. However, some people consider that cloning human embryos with the intention of destroying them shows no respect for human lives.

    While cloning human embryos is illegal in many countries, some scientists are already pushing ahead with the research so as to deliver a cloned human baby. Severino Antinori, an Italian doctor, is one of the leaders in this field of research. He has declared that he wants to be the first to clone a human being.

In China, scientists have focused their efforts on cloning animals, as well as stem cells to be used in medical research. China has succeeded in producing clones of cows and goats, and continues to research ways in which cloning can benefit mankind.

    Would you like to travel? Here is some advice for you.

    Kingsway Hall Hotel

    We offer quality service(优质服务)in Kingsway Hall Hotel. This location puts guests in easy reach of many places, such as the British Museum and Piccadilly Circus. Our hotel also has modern Western food, and offers a perfect dining environment. The lounge bar is a comfortable place to enjoy a drink while watching the tourists. There are hundreds of dining choices within walking distance. Non-smoking rooms are ready for guests.

    Hilton Docklands Riverside

    Located on the bank of the Thames, our hotel is about two miles east of Tower Bridge and 36 miles from London Heathrow Airport. Our hotel has a beauty salon, a flower shop and a swimming pool. The hotel also offers laundry(洗衣店)services, babysitting, shining shoes, and local area transportation.

    Windermere Hotel

    Located in the center of London, our hotel puts guests within easy reach of London's well-known buildings. Buckingham Palace and the Royal Parks are just a short walk away. Within 1. 5 miles you can visit Westminster Abbey and the Houses of Parliament. The theatres, Harrods shopping centre, and the designer shops of Sloane Square and Knightsbridge are all only a short walk away or a taxi ride away.

    Most animals on land are known to us, but many living things underwater are not. Now let's get to know some of them.

    Sea cucumber

    Sea cucumber are strange animals living at the bottom of the sea. They wear brown or white green coats. When summer comes, they stay deep to sleep because they are afraid of heat. And when it is autumn, they move to shallow (浅的) water and get their food.

    Pike

    The pike is a kind of freshwater fish. They are good swimmers and like swimming near boats, waiting to be fed. They have sharp teeth to catch fishes. When they are young, they live in groups. However, when they grow up, they prefer to live alone.

    Cuttlefish

    A cuttlefish can swim quite fast, so it is also called rocket (火箭) fish. It has eight arms and two feelers on its head, just around its mouth. It ejects ink (喷墨) when it is in danger. Its meat is delicious, and it is often the first choice for many people.

    Octopus

    An octopus has long arms, with which to catch food and protect itself. When it is sleeping, one or two of its arms are still on duty, keeping moving. Once it feels something dangerous, it can wake up at once to take action.

    A build-it-yourself solar still（蒸馏器） is one of the best ways to obtain drinking water in areas where the liquid is not readily available. Developed by two doctors in the U. S. Department of Agriculture, it's an excellent water collector. Unfortunately, you must carry the necessary equipment with you, since it's all but impossible to find natural substitutes. The only components required, though, are a 5＇  5＇ sheet of clear or slightly milky plastic, six feet of plastic tube, and a container — perhaps just a drinking cup — to catch the water. These pieces can be folded into a neat little pack and fastened on your belt.

    To construct a working still, use a sharp stick or rock to dig a hole four feet across and three feet deep. Try to make the hole in a damp area to increase the water catcher's productivity. Place your cup in the deepest part of the hole. Then lay the tube in place so that one end rests all the way in the cup and the rest of the line runs up — and out — the side of the hole.

    Next, cover the hole with the plastic sheet, securing the edges of the plastic with dirt and weighting the sheet's center down with a rock. The plastic should now form a cone(圆锥体) with 45-degree-angled sides. The low point of the sheet must be centered directly over, and no more than three inches above, the cup.

    The solar still works by creating a greenhouse under the plastic. Ground water evaporates (蒸发) and collects on the sheet until small drops of water form, run down the material and fall off into the cup. When the container is full, you can suck the refreshment out through the tube, and won't have to break down the still every time you need a drink.

    Being able to take advantage of truly unlimited data is a smartphone user's dream, but everyone I've talked to about 5G is more excited about the usage unlocked by next - generation wireless devices. From smart home security to self - driving cars, all the Internet - connected equipment in your life will be able to talk to each other at lightning - fast speed with reduced delay.

    "5 G is one of those forerunners, along with artificial intelligence, of this coming data age," said Steve Koenig, senior director of market research for the Consumer Technology Association. "Self - driving vehicles are emblematic in this data age - they show application of data completely. With one single task, driving, you have large amounts of data coming from the vehicle itself, and a variety of sensors (传感器)are collecting a lot of information to model its environment as it moves. It's pulling in data from other vehicles about conditions down the road. There's lots of data behind that task, which is why we need the speed and lower latency ((延迟).

    AR glasses and virtual (虚拟的)reality headphones haven't yet been inside the mainstream, but tech companies are joyfully saying that such equipment will eventually replace our smartphones. With 5G, that could actually happen. This is notable because companies such as Apple are reportedly developing AR glasses to improve - or even replace - smartphones.

    Ericsson showed at February's Mobile World Congress in 2019 how smart glasses could become faster and lighter with a 5G connection, because instead of being weighed down with components, the glasses could rely on outside equipment for processing power.

    But don't get too excited. There's still a lot of work to be done in the meantime, including some necessary testing to make sure the radio plays nicely with basic systems and service construction so that 5G isn^'t concentrated only in big cities.

    If you could sail around the world with only one companion, who would you choose? Guirec Soudee, a 24-year-old man from France, chose his pet chicken.

    Soudee has been sailing around the world for two years. No matter which country he sails to, Monique, the hen, is by his side. He found her in the Canary Islands and knew right away they were meant to be best companions. "I didn't speak any Spanish and she didn't speak any French, however, we could always have a small talk, even though she didn't understand me." Soudee joked.

    He had always wanted a companion for his journey and originally thought about bringing a cat, before deciding it would be too much work to look after on a boat. Upon meeting Monique, Soudee realized a hen was the perfect choice. He believed they could communicate with each other well.

    Not only does it cost little to raise Monique, but she lays eggs as well — some things that are always a plus in a situation where storing a lot of food can be a challenge. She lays about six eggs a week on average, even in cold climates like Greenland, where Soudee and Monique are docked(进港) now.

    And what happens when the weather at sea gets bad? Usually Soudee lets Monique stay freely on the boat, but when the winds get terrible he ensures she is safe in her hutch so that she doesn't fall out of his boat and into the sea. Another thing Soudee must care for is the rule in every country he visits. They had met with customs officials in Canada. He was permitted to keep her, but he knows they might not always be so lucky.

    Although Monique can sometimes get on his nerves, Soudee says she's much better than a human companion aboard. "She follows me everywhere. All I need to do is shout 'Monique!' and she will come to me, sit on me, listen to my small talk and give me company," he said.

    After visiting Greenland, they'll head down the Bering Strait to Nome, Alaska. From there the destination is undecided, but Soudee will certainly discuss where they should travel to next with Monique.