Every time we get on a plane, we’re asked to either turn off our phones or change them to flight mode—it’s for “security reasons”.

But according to The Conversation website, having to turn our _________ off on a plane is “a service issue, not a safety one”.

When we speak on our phones in the air, they can cause interference (干扰) to the aircraft’s radios. Pilot can hear this interference in their headphones. “It’s the same _________ you’ll be familiar ( 熟 悉 的 ) with, if you put your mobile too close to a speaker,” the Mirror noted. “It is not safety critical, but is annoying (烦人的) for sure.” Though speaking on a phone during a flight isn’t _________ , from the viewpoint of service, it isn’t still a good idea.

When we make or receive a call on the ground, we connect to a call tower that _________all calls within an 80-kilometer radius (半径). As we move from place to place we are “handed on” to different cell towers.

As US scientist Sven Bilen _________ , for this system to work, there are “built-in” expectations ( 期 待 ): They shouldn’t be too many “handoffs”; people shouldn’t be traveling faster than car speeds and phone users should be close to the _________ .

If we were to make phone calls while we flew, however, none of these expectations would be met. And even _________, our cellphones would stop working.

But now things are beginning to change. If we _________ can’t speak during a flight, we can use other phone functions. For example, Airbus A330 of Emirates Airlines (阿联酋航空) has inflight wifi to make passengers send and receive short messages in the air. In the future, as Bilen points out, it may be _________for air travelers to make and receive calls freely.

The breakthrough could be “pico cells”, which are small cell towers on the phone itself. There would no longer be connections __________ between phones and the ground and therefore there would be no danger of disruption (破坏) to phone service.

One day, perhaps, we will be chatting in the air as much as we chat on the ground.

Everyone knows by now that plastic pollution is a huge problem for the environment. Beijing, for example, has dealt with this by banning (禁止) thin plastic bags, plastic tableware (餐具) and other plastic items in supermarket, restaurants and hotels since May 1, 2020.

But an even better solution might be on the way. Researchers at a French company called Carbios have discovered a bacterial enzyme that can break down plastic. The enzyme, which was first found in compost (堆肥) leaves, turns plastic into chemical “building blocks” that can then be used to create new products, according to the Guardian.

The new enzyme was uncovered in research that was published in the journal Nature. Researchers studied over 100,000 microorganisms (微生物) to find one that could break down plastic quickly. The leaf compost enzyme was first discovered in 2012. Scientists changed its genes (基因), allowing it to break down 90 percent of one ton of plastic in less than 10 hours.

“It had been completely forgotten, but it turned out to be the best,” said Professor Alain Marty, chief science officer at Carbios.

The enzyme especially breaks down PET, a type of plastic that is most commonly used to produce plastic bottles and food packaging. It is the fifth most common type of plastic that we use.

Carbios said it is working together with companies like Pepsi and Nestle—major consumers of plastic themselves—to develop their research and start using the enzyme on an industrial scale (范围), according to Forbes.

Du Fu (712-770), one of the greatest poets in China, is familiar to most of us.

However, Du has remained largely unknown in the Western world.

The one-hour documentary (纪录片) Du Fu: China’s Greatest Poet, introduces the great poet to Western audiences. As the first English-language documentary about Du, it compares him to Dante and Shakespeare, two of the greatest literature (文学) masters of the West.

In the film, British historian Michael Wood explores the poet’s life. He visits a number of places, such as the poet’s birthplace Gongyi in Henan province and the Du Fu Thatched Cottage (杜甫草堂) in Chengdu, Sichuan, where Du used to live. Along the way, he meets and talks to people who help to tell the fascinating story of the poet. The film also includes interviews with scholars (学者) and recitals (朗诵) of Du’s works by British actor Sir Ian McKellen, who is known for performing Shakespeare’s works.

The documentary explains why Du’s works have been popular for centuries. “Chinese people really value the recording of history and Du Fu is better than anyone at reflecting (反映) history in his poetry. That’s because historical events are mirrored in his own life and spiritual (精神的) journey,” said Zeng Xiangbo, a professor at Renmin University.

Du lived under the rule of the Tang Emperor Xuanzong (713-756), a time of prosperity (繁荣). He was a civil servant (文职人员) in the Tang court (朝廷). But as the An Lushan Rebellion of 755 floored the empire, he escaped, took his family on the road as refugees (难民), and suffered starvation (饥饿) and poverty. Through ups and downs, the poet never stopped writing, pouring out his concern for his country and people, as well as celebrating the simple joys of life. Known as China’s “saint of poetry”, he wrote about 1,400 poems that are still with us today.

An exhibition about the Grand Canal—Padding for a Thousand Miles (《周楫千里—大运河文化展》)—ended at the National Museum of China in Beijing on March 1.

The Grand Canal is more than 2,500 years old. It is made up of the Beijing-Hangzhou Grand Canal, the Sui and Tang Grand Canal, and the Zhedong Canal. At n    71     3,200 kilometers long, it is the world’s longest man-made waterway. It has influenced the development of Chinese economics (经济) and culture for h    72     of years.

Before it was b    73     , people in ancient China used horses and oxen, or simply traveled by foot, to trade goods. It was out of the question to transport large-sized goods. After the Grand Canal connected the north and the south, business and cultural exchanges were finally able to develop f    74     .

In fact, the Grand Canal played an i    75     role in the building of the Forbidden City. Materials from different parts of the country were sent to Beijing via the canal, i    76     bricks fired in Shandong and Jiangsu and timber(木材) cut in Hunan. Peking roast duck even owes (把……归功于) its beginnings to the canal. White lake ducks in the s    77     were shipped to Beijing. They were then r    78     to make Peking roast duck.

Zhou Zhihua from Hangzhou grew up next to the canal. He said people from all walks of life — businessmen, dock ( 码头) workers and drivers — would often g    79     along the canal. They shared their e    80    , traditions, and culture with others.

“Today, the hustle and bustle (熙熙攘攘) of the area is just something from the past, but the spirit of openness…has become part of the local culture,” Xinhua noted.

81. 假如你是阳光中学的李华，你所在的学校计划举行关于“阅读习惯”的英语演讲，请你根据以下要点，写一篇演讲稿。