Original sentence: , landscapes and landforms as interpreted by humans), similar to what "supercontinents" and other landmasses are to physical geography, and definitions may vary.Also, Asia is often used in reference to Asia Pacific, which does not include the Middle East or Russia and includes the Pacific Islands.Asia is the largest and most populous of the Earth's continents.Depending on definition, it or may not include Turkey and/or the Middle East and it may or may not include Russia.If is often unclear what Asia precisely consists of.It is traditionally defined as the part of the landmass of Africa-Eurasia lying east of the Suez Canal, east of the Ural Mountains, and southeast of the Caucasus, Caspian and Black Seas.The boundary between Asia and Europe is traditionally believed to run via the Dardanelles, the Sea of Marmara, the Bosporus, through the Black Sea, the Caucasus Mountains, the Caspian Sea, the Ural River to its source, and the Ural Mountains to the Kara Sea at Kara, Russia.The concept of the three continents of the Old World goes back to Antiquity.The demarcation between Asia and Africa is the Isthmus of Suez and the Red Sea
Edited sentence: Also, Asia is often used in reference to Asia Pacific, which does not include the Middle East or Russia and includes Pacific Islands.Asia is a concept that is traditionally defined in the West as the part of the landmass of Africa-Eurasia lying east of the Suez Canal, east of the Ural Mountains, and southeast of the Caucasus, Caspian and Black Seas.However, at times, it is not clear what Asia consists of--it may or may not include Turkey and/or the Middle East and it may or may not include Russia at times.The boundary between Asia and Europe runs via the Dardanelles, the Sea of Marmara, the Bosporus, through the Black Sea, the Caucasus Mountains, the Caspian Sea, the Ural River to its source, and the Ural Mountains to the Kara Sea at Kara, Russia.The concept of the three continents of the Old World goes back to Classical Greek times.The demarcation between Asia and Africa is the isthmus of Suez and the Red Sea.landscapes and landforms as interpreted by humans), similar to what "supercontinents" and other landmasses are to physical geography