2. The railway transportation capacity has been steadily improved.

3. The railway network layout is more reasonable.

4. Railway network operation.

5. The mileage of one-way railway is lengthened.

6. The ability of railway construction to break through natural obstacles has been improved.

Reason: 1. After the founding of the People's Republic of China, the industrialization movement in China laid the foundation for the new China railway construction.

2. The rapid economic growth has provided economic strength for the construction and development of China railway.

The rapid development of science education has improved the ability and level of railway construction in China.

4. The improvement of industrial level has improved the quality of railway raw materials.

5. Reform and opening up and technical exchanges have broadened the horizons of railway construction in China.

Optional question: Diversified diet. There are all kinds of meals.

Reason: Due to the development of economy, the progress of transportation, the flow of domestic population and the strengthening of cultural exchanges between different places, and the reform and opening up, foreign food has entered our country. As the capital of China and the frontier of cultural exchange, Beijing's catering culture is also rich and colorful, realizing the diversification and complexity of its catering structure.