1) The Age of Exploration, during the 15th and 16th centuries, saw European explorers such as Christopher Columbus and Vasco da Gama reach new lands and establish trade routes.

2) The word "elephant" contains three vowels: E, A, and E.

3) In response to the global push for sustainability, many countries have set ambitious goals for transitioning to renewable energy sources, such as the aim to achieve carbon neutrality or significant reductions in greenhouse gas emissions by specific target years.

4) The word "pencil" contains two vowels: E and I.