Answer:
Mountain Ranges.
Explanation:
The natural boundary which shielded the Indus and Ganges Valleys from invaders to the north was mountain ranges. The world's tallest mountains that stood on the north of the Indua valley served as a guard to protect the Indus and Ganges valley from being invaded.
<u>Indus Valley is surrounded by the world's tallest mountain range of </u><u>the Hindu Kush, the Karakorum, and the Himalayas in the north.</u><u> Indus and Ganges valley form the most fertile landforms.</u>
Thus the correct answer is that the natural boundary of mountain ranges guarded Indus and Ganges Valley from being invaded.
The first civilization was Greece, which is in the south-east part of Europe.
The Stone Age marks a period of prehistory in which humans used primitive stone tools. Lasting roughly 2.5 million years, the Stone Age ended around 5,000 years ago when humans in the Near East began working with metal and making tools and weapons from bronze. Paleolithic Period, also spelled Palaeolithic Period, also called Old Stone Age, ancient cultural stage, or level, of human development, characterized by the use of rudimentary chipped stone tools. The Mesolithic is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymously, especially for outside northern Europe, and for the corresponding period in the Levant and Caucasus. Neolithic, also called New Stone Age, final stage of cultural evolution or technological development among prehistoric humans. ... The Neolithic followed the Paleolithic Period, or age of chipped-stone tools, and preceded the Bronze Age, or early period of metal tools. Hominids are the group of primates that includes humans, gorillas, and chimpanzees, among others. The word hominid originally referred only to humans, and its Latin root reflects that: homo, or "man." Today scientists use it to talk about any of the great apes (including humans).
