Which of the following was a key element of the american system? a) abolition of slavery, b) states' rights, c) protective tariffs, d) two-party politics  the answer is c

Protective tariffs  were a key element of the American system. These are tariffs that are enacted aiming to protect a domestic industry. Protective tariffs seek to make imported goods cost more than equivalent goods produced in the country, leading to the rise of sales of domestically produced goods; supporting local industry. Tariffs are also imposed in an attempt to increase government revenue, or to reduce an undesirable activity.

the correct answer is =   british soldiers attacked and killed five boston townspeople.

its main object was the establishment of "settlement houses" in poor urban areas, in which volunteer middle-class "settlement workers" would live, hoping to share knowledge and culture with, and alleviate the poverty of, their low-income neighbors.