【推荐1】A report lasting almost three decades showed that transportation—flying, driving, rail, commercial shipping, etc.—is responsible for a larger share of domestic greenhouse gas (GHG) emissions (排放) than any other economic sector. Though passenger cars currently account for the largest portion of transportation-related GHG emissions, air travel is one of the fastest-growing polluters. In 2018, aircraft were responsible for 9% of U.S transportaton sector GHG emissions and 2.4% of total carbon dioxide emissions globally.

The carbon dioxide emitted from one round-trip flight from New York to London totals about 1,259 pounds per passenger, according to ICAO’ s Carbon Emissions Calculator—that’s more than what the average citizen of Kenya (and more than 30 other countries)emits over a full year.

Planes also leave behind those ice trails (痕迹)—called contrail clouds—which are even more polluting than the CO₂ they produce. The word “contrails” is a mix of “condensation” and “trails”. They occur when waste gases mix with low-temperature, high-humidity (湿度) air. Contrails are harmful not just because they block sunlight, but also because they trap heat coming up from the ground, finally creating a warming effect below.

Today, alternative fuels that are similar in chemistry to traditional fossil jet fuel, but made from waste and raw materials instead, are becoming more commonplace. San Francisco International Airport has already started delivering sustainable aviation (航空) fuel through a pipeline; American, JetBlue, and Alaska Airlines are some of the industry players that have committed to using it.

New research suggests that because contrail louds form only in very low temperatures, reducing the altitude of fights even slightly could dramatically minimize contrail climate forcing. One study found that just 2% of flights in Japan’s airspace were responsible for 80% of that space’s radiative forcing. The same study estimated that if even 1.7% of flights reduced their altitude by 2,000 feet—which is a normal amount of variation from the flight path anyway—the climate impact of contrails could be cut by 59%.

1. What can we learn about air travel in America from paragraph 1?

A．It emitted more CO2 than passenger cars did in 2018.

B．It is the most convenient means of transportation.

C．It accounted for over two percent of global CO2 emissions in 2018

D．It is considered as the largest air polluter recently.

2. What harm will the contrails of the plane cause?

A．Global warming	B．Low temperatures.
C．Expensive flying costs.	D．Increasing water in the air.

3. Why does the author mention the airlines in paragraph 4?

A．To show alternative fuels are much cheaper.

B．To prove alternative fuels are increasingly popular.

C．To announce alternative fuels have a huge effect on the air.

D．To stress raw materials of alternative fuels are common.

4. What does the new research expect airplanes to do to reduce the harm of the contrails?

A．Change their flight paths.	B．Reduce some flight distance.
C．Develop alternative fuels.	D．Fly at a slightly lower altitude.

【推荐2】The world's first underground (地铁) was built in London in 1863. At the time, the government was looking for a way to reduce traffic problems. There were so many people living in the poor areas of the city.    1     If people had an easy way to get to and from work, they would live outside of the city and this would help reduce traffic problems in London. As a result, the idea of the London Underground was born.

The plans for building the London Underground met with several problems.    2     A steam train pulled the cars along the first underground track which was six kilometers long.    3    They were treated to comfortable seats inside the cars. However, the smoke from the engine (发动机) soon filled the air in the tunnels (隧道).    4     Even with its problems, riding the underground did become popular. It carried nine million riders in its first year.

Modern underground has come a long way since the early days of the London Underground.     5     Shopping malls built in traffic stations have helped the popularity of the underground. Nowadays many stations include underground department stores, supermarkets and restaurants. Shoppers never have to go above ground!

A．But the first track was finally opened in January, 1863.

B．It is not easy to build the underground.

C．About 30,000 people got on the underground the first day.

D．Sometimes there are not enough seats for the passengers during rush hours.

E．Fans had to be put in the tunnels later to keep the air clean enough for people to breathe.

F．Today there are more than one hundred underground systems around the world.

G．So the officials decided to make it possible for workers to live outside of London.

【推荐3】Luo Xinlin, 22, experienced her first ride in a self-driving taxi in Changsha, the capital of China's Hunan Province “I made an appointment soon after setting the starting and ending points in the app,” said Liu. “A safety supervisor contacted me and the taxi arrived in about 10 minutes.”

“The taxi drove very smoothly by itself. and the safety supervisor and technician sitting in the front basically didn't have any manual control of it,” said Liu after a 10-minute-long test ride. “The taxi passed through three or four intersections and it was a safe ride without any unexpected situations.”

The self-driving taxi, named Robotaxi, is operated by Hunan Apollo Intelligent Transportation Co., Ltd. based in Xiangjiang New Area in the city. On April 21, the company announced that a group of 30 self-driving taxis had entered public use in the city and users can hail one for a free ride.

“The in-car touch screen can display barriers and dynamic predictions within the 360-degree field of vision and clearly present the conditions of passing vehicles, intersections and traffic lights,” said Cheng Li, director of the test and vehicle operation department of the company. Cheng added users can learn information such as the vehicle's sped and remaining distance through the screen in real time.

In September 2019, the company launched a trial service for a group of citizens, who had to first complete training and other procedures. The technical personnel have started testing self-driving taxis and accumulated a lot of test data since the second half of last year.

China allowed local governments to arrange road tests for intelligent connected vehicles (ICVs), which cover different degrees of autonomous driving, in April 2018. An increasing number of cities, including Beijing, Shanghai and Chongqing, have issued license plates for road tests of ICVs.

1. What is Liu's attitude to self-driving taxis?

A．Mixed.

B．Cautious.

C．Uncertain.

D．Supportive.

2. What do we know about the Robotaxi's test ride?

A．It had unchanging routes	B．No one but the passenger was in it.
C．It allowed passengers to have free use.	D．A safety supervisor controlled it.

3. Which of the following is unavailable on the in-car touch screen?

A．Vehicle operation.	B．The vehicle's speed.
C．Road conditions	D．Remaining distance.

4. In which section of a newspaper may this text appear?

A．Fashion.

B．Technology

C．Society.

D．Business.

【推荐3】Have you ever fantasized about how easy life would be with a personal assistant taking care of all the “little details”? Nowadays, you can get lots of the advantages of an AI assistant right on your phone or computer. Using any of these apps will help you improve your efficiency and productivity with a single click—whether you are at work or at college, or anything else in between. So go forth and download the best AI assistants:

◇ Utter. AI If you’ve been looking for a better companion to help you with taking notes during meetings or lectures, Utter. AI is the right one. Utter. AI is an intelligent- dictation app which not only takes notes and records the audio but also transcribes the text and has a highlight summary. The app offers up to 600 minutes for free and has an Utter Pro subscription for $8. 33/month. ◇ Nound Nound is the perfect voice assistant researching tool you need. It doesn’t just allow you to search for the nearest subway, or what the weather will be like, with a further question or two you can get more in-depth results. Some reviews claim it’s the fastest and most intelligent app of its kind. Nound is a free app, but for $ 6.99 you can eliminate (清除) in-app ads and use some extra features. ◇ StayFocusd StayFocusd is a free browser extension that improves your productivity by blocking those distracting websites that stop you from working or studying. It gives you total control with the ability to block websites either by time and date, or by time limit. StayFocusd is a free Chrome extension. ◇ EasilyDo EasilyDo offers personal assistant services focused on communications. With just a few clicks you can customize your email notifications, back up important messages, organize your contacts, have junk and expired emails automatically deleted, and collect attachments and receipts into one, fast-access location. ◇ Time. AI Before you can improve your productivity habits, you need to know where you’re spending your time. Time. AI does exactly that. It records how much time you’re spending on the different apps and websites. Once it has a full report it will show you your statistics and tell you when you’ve been productive and when you haven’t. With the report, you can set daily “Focus Work” goals and it will keep track of it to make sure you’re doing the work you want to do. Time. AI gives you a 30-day free trial and will give you a special price depending on your unique needs.

1. Which of the following can offer help to locate an ideal hotel?

A．Utter. AI.

B．Nound.

C．StayFocusd.

D．EasilyDo.

2. “Time. AI” is to help you ______.

A．take notes	B．understand your needs
C．keep focused	D．detail your daily routine

3. The passage is written to ______.

A．emphasize the importance of AI assistants

B．recommend some AI-powered apps

C．offer advice to personal assistants

D．explain the way apps work