• "The mixture of gases that surrounds the Earth" is called - Atmosphere.
• Atmosphere (Noun):
- English meaning: The mixture of gases that surrounds the Earth.
- Bangla meaning: বায়ুমন্ডল।
• Other options:
- Anthropology: The study of the human race, especially of its origins, development, customs and beliefs.
- Bangla meaning: নৃতত্ত্ব; নরবিজ্ঞান; মানুষের উৎপত্তি ও বিকাশ-সম্বন্ধীয় বিজ্ঞান; নরবিদ্যা;।
- Geography: The scientific study of the earth’s surface, physical features, divisions, products, population, etc.
- Bangla meaning: ভূগোলবিদ্যা।
- Demography: The changing number of births, deaths, diseases, etc. in a community over a period of time; the scientific study of these changes.
- Bangla meaning: জনসংখ্যা; জনতত্ত্ব;।
Source: Merriam-Webster Dictionary, Oxford Dictionary, English-Bangla Dictionary.