You can develop vocabulary by reading and communicating with others who speak the language that you are building your vocabulary in. You can also write down words and their definition that you do not understand so you can remember better next time. Finally, use words that you just learned so that you will be able to remember them better. This will help you build your vocab.
Silent Spring by Rachel Carson was an environmental science book. It documented the negative effects the indiscriminate use of pesticides has on the environment, particularly the birds.
The book became the tool that awakened the public to the real harm that big industrial companies have been hiding from them. Thus, driving them to launch an environmental movement that aims to prohibit the indiscriminate use of pesticides, specifically DDT.
Barbary pirates are pirates that plundered thousands of merchant ships of many nations and they attack coastal towns. They are named berbers which is of North Africa origin. They hail from Morocco, Tunis, Algiers, Arabs, Tripoli, mostly Muslim countries and few Christians from Europe.