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 highest-grossing concert tour of all time is U2's "360° Tour," which earned over $735 million in ticket sales.

3) The Edelweiss flower, found in the European Alps, is known for its beauty and is often associated with mountaineering and alpine culture.

4) The Nile River, spanning approximately 6,650 kilometers (4,130 miles), is the longest river in the world. It flows through eleven countries in northeastern Africa, supporting various civilizations throughout history and serving as a vital source of water and transportation.