"<span>They relied on a single, long growing season for rice." is the best option from the list, although they did eventually produce silk which led to thriving trade with Europe.</span>
Answer:
Explanation:
Natural fortifications also helps defend a country. For example the Alps in Italy defends them very well. Rivers can also be a defensive position a country can fall back to. So no, fortifications and defenses arent the only thing. Nature is able to help too.
<span>Agriculture allows us to settle down permenantly in a particular area (without having to move around from place to place). Agriculture allows us to expand our population rapidly, and it also encourage diversification of work. Because there are farmers to provide us with food, others can do other work such as be teachers, students, politicians, doctors, engineers, artists, etc., etc. In other words, agriculture encourages the development of a more complex society in terms of sociology, economy, politics, education, and culture. </span>
D. 18th Century, 19th Century, 20th Century.