6 . Taihu Tunnel, 10. 79 kilometres long and 43. 6 metres wide, has been the longest underwater tunnel in China. It stands out as one of the “2022 China’s Top 100 Buildings in the New Era”.
When building Taihu Tunnel, the project team faced many challenges, such as high safety risks and time limit. To deal with them, they made workable plans. They divided the tunnel construction into 19 parts. The construction of each part mainly took four steps.
Step 1 Remove. The team built a cofferdam to remove water from the area, so the workers could go inside and do their work in dry conditions.
Step 2 Clear. The team dug deep into the lake bed, and cleared the soil and stones out in order to make space for the next step.
Step 3 Build. The team built the floor, walls and roof of the tunnel in this step. They used high-quality building materials to waterproof the tunnel.
Step4 Backfill. The team put the soil and stones back. Then this part of the tunnel was buried deep down the lake bed.
The construction of the 19 parts was streamlined. The project team used a new method. The work group of each step moved to the next part and repeated their work after they finished the work in the previous part. Different work groups co-operated well with each other. From part to part, the construction started from the opposite ends, and got connected somewhere in the middle. The construction took about four years to complete, shorter than people had expected.
The drivers’ safety is fully considered in 1aihu lunnel. There are 200, 000 LED lights on the ceiling of the tunnel. They show vivid pictures of blue sky, starry night and so on. The pictures can help drivers fight tiredness and travel through the tunnel safely. Besides, there are two systems in the tunnel. The police can check the traffic situation through a monitoring system. If traffic accidents happen, the police can give instructions and warn drivers in the tunnel over an audio system to prevent further accidents.
The construction of Taihu Tunnel shows great value in engineering and the tunnel brings much convenience to people living nearby.
1. Which picture shows how a “cofferdam” works?
2. The construction of Taihu Tunnel ________.
| A．was divided into four parts | B．took more time than people had expected |
| C．started from the middle of the lake | D．was completed by using a streamlined method |
3. What can we learn from Paragraph 8?
| A．Pictures in the tunnel can help keep drivers safe. |
| B．Drivers can control the LED lights in the tunnel. |
| C．The police can warn drivers through a monitoring system. |
| D．An audio system can help drivers check the traffic situation. |
4. What is the main purpose of the passage?
| A．To advise people to protect Taihu Tunnel. |
| B．To introduce the construction of Taihu Tunnel. |
| C．To share the advantages brought by Taihu Tunnel. |
| D．To tell the difficulties of constructing Taihu Tunnel. |
