It took years     1    (complete) the Qinghai-Tibet Railway. The construction workers     2    (overcome) the most difficult engineering challenges，one of which was how to protect the delicate ecosystem.To allow the wild animals to move safely and freely in their     3    (nature) habitat，they built thirty-three passages under the railway. To prevent damage to wetlands and grasslands，675 bridges with a total length of about 160 kilometres     4    (build) between Golmud and Lhasa. They even moved 140，000 square metres of wetland to     5     new area in order to protect its distinct ecosystem.     6    (locate) at over 5，000 metres above sea level，Tanggula Station is the highest railway station in the world. In locations such as this，the thin air，changeable weather and high levels of UV radiation presented perhaps the     7     (great) challenge for railway workers. To make sure they stayed healthy，several oxygen-making stations were constructed. To protect Cuona Lake     8     construction waste，the railway workers used thousands     9     thousands of sandbags to build a twenty-kilometre wall along the lake. In a word，the railway workers built our “impossible” railway with the care that the environment deserves. It     10    (true) is an extraordinary “Sky Railway”.

As the countdown (倒计时) to the 2022 Beijing Winter Olympics continues, the new high-speed railway line     1     (connect) the capital with Olympic host city Zhangjiakou has just entered service. It cuts the travel time between the two from three hours to 47 minutes. But this isn’t just another common bullet train.     2     (consider) to be the world’s first smart high-speed railway, this beauty, part of China’s Fuxing series, can run up to 350 kilometers per hour without     3     driver.

So what makes them “smart”? Well, the train cars     4     (equip) with 5G signals, intelligent lighting and sensors to collect real-time data and detect any operational abnormalities. Meanwhile, each individual seat has     5     (it) own touch-screen control panel and wireless charging docks. Though the high-speed trains on the route are autonomous, a monitoring driver will be on board at all times. The trains can start, stop and adjust automatically     6     different speed limits between stations. Back at the station, robots and technologies of facial     7     (recognize) can help passengers with directions, luggage and paperless check-ins.

Today, China is home to the world’s     8     (large) high-speed rail network, and the fastest    9     (commercial) operating train — the Shanghai maglev. According to the China State Railway Group, 1,036 Fuxing bullet trains have been put into operation since 2017     10     the series were first made public.

Car registration plates (牌照) are just a series of numbers and letters, right? Well, yes…but not for everyone.

France was the first country     1    (introduce) plates in 1893. Early number plates differed     2    shape and size, and were made of lots of different materials, including iron, cardboard and even pressed soybeans. In fact, it was not until 1957     3    car manufacturers and the governments agreed on standardized(标准化) plates.     4    was first registered in the UK was A1. The letter “A” showed the number was from London, while the number “1” showed it was the first number issued. At the moment, number plates     5     (consist) of a sequence of letters and numbers are applied in the UK.

Different EU countries also use different arrangements of numbers and letters, and     6     systems have changed many times because these letter-number     7     (combine) keep running out. In the past decades, some number plates     8     (become) extremely valuable, particularly those that spell out words.     9     (basic), numbers on the plates can be used to represent words or parts of words. For example, “NVERLA8” means “Never Late”. And the most     10     (expense) number ever was “M1” which an anonymous(匿名的) buyer has acquired for ￡331,000.

The Hong Kong-Zhuhai-Macao Bridge, the world's     1    (long) cross-sea bridge, enters the history of human engineering and connection as a point of pride upon     2    （it) opening to traffic at 9 am on Oct.24, 2018.

One day after the opening was announced at a ceremony     3    (hold) in Zhuhai , the bridge's ports in three different administrative regions started serving travelers around-the-clock , opening 24 hours a day, seven days a week.    4    (ensure) faster boundary crossings for passengers, the Macao and Zhuhai ports jointly use a one-off immigration clearance model,    5    allows travelers to queue up only once to finish both exit and entry procedures of the two cities in about 30    6    (second).

Apart    7       private cars, taxis and goods vehicles, two types of public transportation -shuttle bus（班车）and cross-boundary coach --can also run on the HZMB.     8    frequency of shuttle buses is about 5-10minutes during peak hours. Booking tickets for the shuttle bus online in advance     9    （be）available since 9 am on Tuesday. With the bridge now in service, the traveling time between Zhuhai and Hong Kong International Airport will    10    ( shorten) from four hours to 45 minutes, and the time between Zhuhai and Hong Kong’s Container Terminals will be cut from 3. 5 hours to 75 minutes.

China has built a high-speed passenger rail network in recent     1     (year) and will continue to expand it. By the end of 2018, China's railway mileage (里程)    2     (reach) 131,000 kilometers, of     3     29,000 kilometers were high-speed rail. This accounted for 2/3 of the world's total high-speed rail tracks, making China's high-speed rail system the world's     4     (large) high-speed rail network.

China's high-speed trains are similar     5     those of France's TGV, German's ICE and Japan's Shinkansen. The fast trains with a top speed of 250-350 km/h     6     (call) CRH, China Railway High-speed.

If you want to travel around China, the high-speed trains will be your ideal choice since they are clean, comfortable     7     modern. Unlike on the conventional trains in China, nobody is allowed     8     (smoke) on high-speed trains, not even between carriages.

The seats are as good as those on the plane or even better. Most high-speed rail tickets have corresponding (对应的) seats, and only     9     small number of standing tickets are sometimes sold on limited trains. There's never a crowd of people sitting in the aisles. The ticket prices for China high-speed trains are reasonable and, on most routes, the frequency of departure is very high, so people can buy tickets    10    (convenient).

It's common to see food delivery workers riding electric bikes in a hurry through big cities in China. Some of them even risk     1     (run) red lights to deliver their meals in time. However, such careless behavior often causes serious problems.

The reason for the rise of such a careless behavior is that there is     2     large demand for food delivery workers, and many companies offer high salaries     3    (attract) new workers.

In fact, food delivery workers are often under high     4    (press) from their employers. They face company fines for delivering food late. Moreover, the more orders they take, the more money they can earn,     5     leads to some workers checking     6    (they) mobile phones for new orders while they are riding their bikes

While most companies require delivery workers to follow traffic rules, it remains a problem whether these requirements and rules are     7    (strict) obeyed

To solve the problem, some cities     8    (take) action since last year. Shanghai required the delivery workers should    9    (train) on traffic rules and safety. Now in Shenzhen, if a delivery worker gets caught breaking traffic rules more than twice, he or she will be banned     10     driving food delivery vehicles for a whole year.