by air的音標是[ba? ɑ?(r)]，基本翻譯是“乘飛機”，速記技巧是：比愛肉（諧音）飛（飛機）。

by air的英文詞源是拉丁語，意為“通過空氣”。它的變化形式包括：

1. by air（乘飛機） - 由空氣或空中運輸的意思，常用于表示乘坐飛機出行。

2. airmobile（航空的） - 由air和mobile兩個詞組成，表示與空氣相關的、能夠移動的。

3. aerial（空氣的，航空的） - 詞源同air，表示與空氣相關的。

by air的相關單詞有：

1. airline（航空公司） - 指提供空中運輸服務的公司。

2. aeroplane（飛機） - 指用于空中運輸的工具。

3. take off by air（乘飛機起飛） - 指通過空中運輸工具離開某個地方。

4. land by air（乘飛機著陸） - 指通過空中運輸工具到達某個地方。

5. air traffic control（空中交通管制） - 負責控制空中交通的機構或人員。

6. airborne（空中的） - 指在空中飛行或運輸的。

7. airlift（空運） - 通過空中運輸方式進行的運輸方式。

8. airmail（航空郵件） - 通過空中運輸方式發送的郵件。

9. air freight（航空運費） - 指通過空中運輸方式支付的費用。

10. air transport（航空運輸） - 指通過空中運輸方式進行的貨物或人員運輸。

這些單詞都與by air這個短語有關，表示通過空中運輸的方式進行各種活動。

常用短語：

1. by airplane

2. by airmail

3. by helicopter

4. by airlift

5. by private jet

6. by airfare

7. by airbridge

例句：

1. I took a flight to New York by airplane.

2. Please send this letter by airmail.

3. The helicopter landed on the helipad.

4. The city was airlifted to safety during the earthquake.

5. He owns a private jet and flies around the world.

6. The cost of airfare has gone up recently.

7. We need to build an airbridge to connect our two cities.

英文小作文：

Air Travel - A Great Way to See the World

Air travel has become an essential part of modern life, allowing us to visit faraway places and meet new people with relative ease. From airplanes to helicopters, private jets to airbridges, air travel has opened up a world of possibilities for those who choose to take to the skies.

Whether it"s for business or pleasure, air travel has become a popular way to see the world. It"s fast, convenient, and allows us to escape from our daily routines and immerse ourselves in new cultures and environments. From the bustling cities to the serene beaches, we can experience it all from the comfort of an airplane.

However, air travel also comes with its challenges and concerns. Air travelers need to be aware of safety regulations and procedures, as well as the environmental impact of flights on our planet. But with advances in technology and better policies in place, air travel is becoming safer and more sustainable, making it an even more attractive option for those who want to see the world.

In conclusion, air travel has become a popular way for people to see the world. It"s convenient, fast, and allows us to experience new cultures and environments. But it also comes with its challenges and concerns, and we need to be aware of these as we continue to embrace air travel as a way of getting around.