1) The role of lobbyists in politics involves representing the interests of specific groups or industries and advocating for favorable policies or influencing decision-making processes within government institutions.

2) The process of impeachment involves charging a public official, such as a president or high-ranking government official, with misconduct and potentially removing them from office through a trial and vote by the legislature.

3) The concept of gravity was famously described by Sir Isaac Newton after an apple fell on his head.

4) The word "guitar" contains three vowels: U, A, and I.