Every early morning in Southwest China’s Chongqing, there is a common scene at the city’s Rail Transit Line 4: A group of farmers 【小题1】 (shoulder) vegetables for sale are busy riding on the subway to downtown.

Nicknamed “packbasket special line”, the second phase of the subway line, connecting Shichuan town to the city center, has 【小题2】 total length of 32.8 kilometers and 15 stations. It 【小题3】 (provide) local farmers near the town with a wider channel for selling their produce since its opening.

Every morning around 6 o’clock, the entrance and exit of the Shichuan Town station of the line are 【小题4】 (crowd) with these special commuters (上下班往返的人) 【小题5】 baskets are filled with fresh seasonal vegetables. It took them more than one hour 【小题6】 (reach) the city before the opening of the line as they had to take several buses. Now, by taking the subway, they can get there in less than 30 minutes 【小题7】 any difficulty. The opening of this subway line not only saves money for the farmers but also time, bringing great 【小题8】 (convenient) to them.

To facilitate the farmers, the station, which was supposed to open at 6:15, now opens five minutes earlier every day. The staff members 【小题9】 (arrange) at the station also assist as much as possible: guiding them to 【小题10】 (efficient) enter the station in order and to use the elevators, and helping them with the baskets.

I was one of the people 【小题1】 work on Qinghai­Tibet Railway，which was completed by 【小题2】 (overcome) the most difficult engineering challenges to protect the delicate ecosystem.To allow animals to move 【小题3】 (safe) and freely，thirty­three passages have been built.To prevent damage to wetlands and grasslands,675 bridges，which is about 160 kilometres in 【小题4】 (long)，were build and 140,000 square metres of wetland 【小题5】 (move) to protect its distinct ecosystem.Tanggula Station，【小题6】 (locate) at over 5,000 metres above sea level，is the highest railway station in the world.To keep us 【小题7】 (health)，several oxygen­making stations were constructed.To protect Cuona Lake 【小题8】 construction waste，a twenty­kilometre wall was built.Thanks to our 【小题9】 (effort)，passengers who have been attracted by the Qinghai­Tibet Plateau，have been enjoying these 【小题10】 (magic) landscapes.

In 1863 the first underground passenger railway in the world opened in London. It ran for just under seven kilometers and allowed people to avoid terrible 【小题1】 (crowd) on the roads above as they travelled to and 【小题2】work. It took three years to complete and was built using an interesting method. This included digging up the road, 【小题3】 (lay) the track and then building strong roof over【小题4】 top. When all those had been done, the road surface was replaced.

Steam engines 【小题5】 (use) to pull the carriages and it must have been 【小题6】 (fair) unpleasant for the passengers, with all the smoke and noise. However, the railway quickly turned out to be a great success and within six months, more than 25,000 people were using it every day.

Later, engineers 【小题7】 (manage) to build railways in a system of deep tunnel (隧道)，【小题8】 became known as the tube. This development was only possible with the【小题9】(introduce) of electric-powered engines and lifts. The central London Railway was one of the most 【小题10】 (success) of these newlines, and was opened in 1900. It had white-painted tunnels and bright red carriages, and proved extremely popular with the public.