heavier-than-air

heavier-than-air的音标是["hi:viə,-ti:ən] ，基本翻译是“重于空气的”。速记技巧可以是：hit=重，tan=than空气，组合起来就是“重于空气”的意思。

heavier-than-air：

1. 词源：该词源自拉丁语“heavier than air”，意为“比空气重”。

变化形式：该词在英语中通常使用其动词形式和过去分词形式，如“to be heavier than air”和“heavier-than-air”。

相关单词：

1. lift（提升）：该词源自拉丁语“levare”，意为“抬起”或“提升”。lift的动词形式“lifting”可以用来描述通过使用重物或机械装置将物体提升到空中。

2. weight（重量）：该词源自拉丁语“pes”，意为“重量”或“重”。weight的形容词形式“heavy”可以用来描述物体或物质的质量。

3. buoyancy（浮力）：该词源自英语单词“buoy”，意为“浮标”或“浮起”。浮力的概念是指物体在液体或气体中由于受到浮力而产生的向上或向下的力。

4. air resistance（空气阻力）：该词由两个部分组成，“air”和“resistance”，意为“空气的阻力”。空气阻力是指物体在空气中运动时受到的阻碍。

5. density（密度）：该词源自拉丁语“densitas”，意为“密度”或“稠密”。密度是指物质单位体积的质量，是物质的一个重要属性。

6. aerodynamics（空气动力学）：该词由两个部分组成，“aero”和“dynamics”，意为“空气的动力”。空气动力学是研究空气与物体相互作用的一门学科。

7. lift-off（起飞）：该词表示物体从地面或平台起飞的过程。lift-off通常用于描述飞机、火箭或其他飞行器从地面或平台上起飞的情况。

8. subsonic（亚音速的）：该词表示低于音速的速度。subsonic通常用于描述飞行器在低速飞行时的状态。

9. supersonic（超音速的）：该词表示高于音速的速度。supersonic通常用于描述飞行器在超音速飞行时的状态。

10. aeronautics（航空学）：该词由两个部分组成，“aero”和“nautics”，意为“空气的航行”。航空学是研究航空器及其在空气中的运动的一门学科。

常用短语：

1. heavier than air

2. lighter than air

3. air-conditioning

4. airborne

5. air pollution

6. air quality

7. atmospheric pressure

例句：

1. The balloon is heavier than air and floats in the air.

2. The ship is powered by a system of air-conditioning to keep the passengers comfortable.

3. The airborne virus is spreading quickly through the community.

4. Air pollution is a serious problem in this city.

5. The air quality in the forest is much better than in the city.

6. The atmosphere is under high atmospheric pressure today.

7. The weight of the air above the ground is much greater than that of the ground itself.

英文小作文：

Air is a vital part of our environment, and it plays a crucial role in our lives. However, air has a weight, and it can be heavier or lighter than air depending on its composition and density. When we talk about heavier-than-air objects, we are usually referring to objects that can float in the air, such as balloons or airplanes, which are supported by the buoyancy of the air. On the other hand, lighter-than-air objects are usually supported by a force other than gravity, such as magnetic fields or buoyancy from the water surface. In addition, air has many other important functions, such as providing temperature regulation and transportation of gases and particles. Understanding the role of air and its properties is essential for maintaining a healthy and safe environment for all living beings on Earth.