题目

There are safety regulations that limit how high planes can fly. These regulations ensure the safety of aircraft operations and the protection of airspace. In general, commercial aircraft operate at altitudes (高度) between 30,000 and 40,000 feet, while private planes may fly lower depending on their type and purpose.Different types of aircraft operate under various air traffic regulations. Commercial jets typically fly at higher altitudes due to their size and engine capabilities, which allows them to avoid turbulence (湍流) and optimize fuel efficiency. In contrast, smaller private planes usually fly at altitudes below 25,000 feet. This altitude difference is partly due to the limited capabilities of smaller aircraft and the need to maintain safe distances from commercial traffic.The positive aspect of these regulations is that they enhance safety in the skies. For example, the Federal Aviation Administration (FAA) ensures that aircraft maintain vertical (垂直的) separation from each other at flying altitudes. This reduces the risk of mid-air collisions (碰撞). Additionally, operating at higher altitudes allows planes to avoid weather disturbances, such as thunderstorms and turbulence, further improving passenger comfort and safety.On the negative side, altitude restrictions can limit the operational flexibility of some aircraft. Smaller planes may be restricted by regulatory limits, which can hinder (阻碍) their flight paths and efficiency. According to a study by the National Transportation Safety Board (NTSB) in 2019, lower operating altitudes can increase exposure to obstacles such as buildings and terrain, raising safety concerns for private pilots.To optimize flight safety and efficiency, pilots should adhere to regulatory altitude limits based on their aircraft type. They should also consider factors such as weather conditions and airspace restrictions. For private pilots, flying in controlled airspace may require altitude adjustments to ensure obedience. It is essential for all pilots to stay informed about regulations from agencies like the FAA to make safe and informed flight decisions. （1） What can we know from Paragraphs 1-2? A . Private jets fly lower to avoid turbulence. B . Different types of aircraft operate under the same air traffic regulations. C . Flying at higher altitudes help commercial planes use fuel efficiently. D . Smaller planes operate at altitudes between 30,000 and 40,000 feet. （2） What is a potential drawback of altitude rules for smaller private planes? A . They consume more fuel. B . They are exposed to more obstacles. C . They cannot fly in controlled airspace. D . They are unequally treated as commercial jets. （3） What does the underlined phrase "adhere to" in the last paragraph mean? A . Create. B . Adjust. C . Illustrate. D . Follow. （4） What is the author's purpose in writing the text? A . To introduce distinctions between two types of planes. B . To explain different flying altitudes of commercial and private jets. C . To show the background of safety regulations. D . To explore how planes avoid weather disturbances. 答案： C B D B

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