Buses are celebrating their 100th anniversary. About 80 percent of all public-transport passengers worldwide are carried by buses. The bus is a very efficient mode of transport, being cheap, flexible, comfortable and, in many cases, tailored to the needs of users both in terms of capacity and speed. Buses operate in mixed traffic, and are easy to put in service. From an economic, environmental and social point of view, the bus remains the best solution to the problem of achieving balanced and environmentally-friendly urban development. Indeed, the bus is the only mode of public transport in many of the world’s cities, and plays a key supporting role in cities with rail transport. Over the past decades, increased use of roads by private cars has contributed to terrible traffic problems, affecting the speed of buses as well, and hence their service quality, reliability, energy consumption, and economy. In such circumstances, the efficiency and performance of buses depends heavily on special lanes. Various forms are possible----from a mere painted mark on the road to more expensive variants such as elevated lanes, movable barriers, and “bus locks”. A related trend is to look beyond vehicle technology alone and to consider the wider system, of which buses are a part, such as the infrastructure(基础设施)and other operational aspects of city. This is commonly known and promoted as the “bus-system approach”. Other key innovations(革新) include clean engines, alternative fuels, and guidance devices. In terms of the designs of buses, much of what has happened to light rail can be transferred to them, including the shapes of the vehicles themselves. The energy consumption of a bus per passenger is one-sixth that of a car, and buses are only responsible for about 5% of the CO2 emissions generated by vehicles at present. 1. From this passage we learn that_____________. A. buses are the most environmentally-friendly of all motorized vehicles B. buses were first used more than a century ago C. most passengers prefer trains to buses D. a bus has a much larger capacity than any other vehicle 2. What has affected the service quality of buses? A. Unsuitable infrastructure.                      B. Private cars. C. The increasing population of cities. D. Very rapid urban development. 3. Which of the following is an approach to improving bus service? A. Improving the speed of buses. B. Reducing the number of private cars. C. Setting up special lanes for buses. D. Increasing the number of buses. 4. From the passage we can infer that in the future_____________. A. there will be more buses than today B. bus engines will need no power C. buses will be replaced by other means of transport D. the appearance of buses will change