What will the world be like if cars can drive themselves? Imagine seeing an empty car passing by on its way to pick up its owner or a car full of passengers who are reading, listening to music or even sleeping. The passengers in the car needn't worry about the road ahead.

    Well, all of this could be the future of driving. There are several companies, including Google, Tesla, Mercedes-Bens, Audi, BMW, Volvo and Toyota, working on driverless cars. They are now in the testing stages (阶段). If the tests are successful, these self-driving cars could be available very soon. But how is it possible for a car to drive itself?

    Modern cars are able to take the place of drivers during certain situations. For example, they can park themselves or slow down when they detect (发现) objects nearby. They can also control the speed if there are dangerous condi-tions, such as snowy roads. Scientists and engineers believe that, with the help of wireless signals (无线),cameras and GPS, creating a safe self-driving car might be possible in ten to twenty years.

    Self-driving cars may help cut down the number of serious accidents caused by careless drivers or dangerous condi-tions. However, there are still some people who do not like the idea. American lawyer, White Drake, for example, doesn't believe these cars are safe. He thinks the possibility of the technology making a mistake will be too high.

    Shanghai University of Engineering Science has become the first university in China to be covered by a 5G network, the university announced on Tuesday.

    Chinese mobile carriers(运营商) are expected to spend 1.2 trillion yuan（US＄176.5 billion） on 5G by 2025,50 percent more than their total 4G investment (投资), Nomura said yesterday. Carriers including China Mobile, China Telecom and China Unicom, are expected to build over 4.9 million 5G base stations by 2025.

    5G is a" game﹣changing" opportunity for carriers as they can explore new business like smart manufacturing, super high definition video and smart driving, instead of just being a "pipeline" for voice and data services.

    China will supply "temporary "5G licenses in several aimed cities this year. Consumers(消费者) will be able to use the first batch of 5G smart﹣phones and tablet computers in the second half. It's the first time that China's top industry regulator clarified the 5G industry timeline, especially the first appearance of 5G phones.

    But 5G services will become accessible to normal consumers later than expected. More work needs to be done to make the 5G industry fully developed, which won't happen until 2020, said UBS recently. New business projects and organizations, rather than normal consumers, will enjoy 5G services at first. The first batch of 5G services will be available to consumers in about 10 cities only.

With our already busy lives, finding time to exercise can be impossible. So maybe it would help if there was ‘a best time' to exercise.

There are clear benefits to exercising in the morning. Many of us have more free time than later in the day, and it may be easier for us to keep a morning plan. A study found that people could sleep better when they exercised in the morning or had the physical activity during the whole day. Exercising on an empty stomach（空腹）before breakfast could also have less fat（脂肪）and keep healthier.

So, good news for early birds, but what if you're not a morning person? Working out in the afternoon or evening is also good, but different. For example, your body's ability reaches the highest level in the afternoon, according to a 2010 study. Also, in the afternoon and evening, your mind is the quickest, and your heart rate and blood（血）pressure are lowest, and you aren't getting hurt（受伤）easily when exercising.

But can this happen? Deciding on if you are a man or a woman? Our bodies are different, after all, so the best time to exercise may be different too. Want to reduce（降低）your blood pressure and you are a woman? Exercise in the morning. Want to improve your heart health and you are a man? Evening is better for you. But, a 2022 study found that it's both OK for them to exercise at either time of day.

So what time is best? It seems the answer is: whatever time is best for you!

My sister and I are different from each other. I like music very much, so I {#blank#}1{#/blank#} play the piano in my free time. But my sister {#blank#}2{#/blank#}tries to

play the piano because she hates it. She doesn't like sports but she {#blank#}3{#/blank#} plays badminton to keep fit. We are close to each other though we have different hobbies. We {#blank#}4{#/blank#} fight with each other unless we are really angry.

My good memory is often seen as something that we are thirsty for, while a bad memory as something that can hardly be changed. {#blank#}1{#/blank#} ,. Here are some tips（贴士） for you.

◆ Take an interest

We all remember the things we are interested in, and always forget the ones that bore us. This explains the reason why school boys remember football results easily but struggle（挣扎）with dates from their history lessons! Develop an active interest in what you want to remember. {#blank#}2{#/blank#}

◆ Repeat things in chunks（块）.

Repeating things in chunks is the best way to remember things in a short time, for example, remembering a long number for a few seconds. {#blank#}3{#/blank#}

 The following numbers would be impossible for most of us to remember: 1492178919318483. But divide them into "groups" or "chunks", and it becomes much easier: 1492 1789 1931 8483.

◆ {#blank#}4{#/blank#} .

It's another good way to make up a story which includes all the things you want to remember. In experiments, people were asked to remember up to 120 words using this way. When they were tested later, they could remember about 90% of them. {#blank#}5{#/blank#}