1. The first question asks why trade by rivers was so important during India's Vedic Age. 2. The key reason is that roads were not well made, making land travel difficult. 3. Rivers provided natural, efficient routes for transporting goods and people. 4. The climate and terrain limited overland travel, so rivers were the main trade arteries. 5. Therefore, the correct answer is: The roads were not well made. 6. The second question asks for the best example of a main belief of the Hindu religion. 7. Hinduism is known for the belief in rebirth after death, also called reincarnation. 8. This belief is central to Hindu philosophy and distinguishes it from monotheistic systems. 9. Therefore, the correct answer is: Rebirth after death. Final answers: - Trade by rivers was important because the roads were not well made. - A main belief of Hinduism is rebirth after death.