<span>Railroads used the iron to build railroad tracks but iron was weak and also dangerous. Soon people then realized that steel was a better material for tracks because it was able to hold more weight which then allowed heavier cargo. Railroads also transported mineral needed to forge steel.</span>
<span>Rationalism is a philosophical movement which gathered momentum during the Age of Reason of the 17th Century.</span>
2. Letter B. The Sikhs challenged the view on the caste system with the concept of equality regardless of their genders, caste, class or ethnicity. They also does not promote the idol worshiping of individuals unlike the caste system which gives much importance to the Brahmins.
3. Letter C. Hindus. Until today, there are still tension between the Muslims and Hindus in India. This tension was especially great during the creation of Pakistan. Today there are still territorial disputes between these nations.
4. The best the choices would be D. But the reson they continued to prosper was because they move and was protected by the Huang River from the constant invasion from the North.
