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.

2 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式,并将答案填写在答题卡上。

Trains are cleaner, greener, more spacious and     1     (general) less troublesome than planes. Once     2    (view) as travel’s past, rail is now starting to look a lot like the future. In the USA, a huge expansion of the train network is drawing     3     (people) attention. And in Europe, some very cool plans have been made for a whole new generation of sleeper trains.

Sleeper services,     4     operate overnight between major destinations, get rid of the main disadvantage of train travel: the lengthy journey time. Like a red-eye flight on rail, you can board the train in the centre of one city and wake up in     5    , ready to drink a cup of coffee and explore.

Once numerous, Europe’s night trains have been cut back gradually over recent decades. But that trend is reversing (逆转).We’re very excited to hear about the     6     (announce) of five new European night train routes, launching over the next four years. A total of eight European countries     7     (link) by the new routes.

    8     short, your European travels over the     9     (come) years are going to involve hanging around not at airports     10     through railway stations. Needless to say, we’re into it. All aboard!