1) The Rocky Mountains, also known as the Rockies, extend from Canada through the United States, offering stunning landscapes and outdoor recreational opportunities.

2) The concept of proportional representation, used in some electoral systems, aims to ensure that political parties' representation in government aligns more closely with the proportion of votes they receive from the electorate.

3) The COVID-19 pandemic has highlighted the importance of global collaboration and solidarity in addressing public health emergencies, with efforts focused on vaccine sharing, equitable distribution, and support for developing countries.

4) The development of the microprocessor by Intel in 1971 paved the way for the modern computer and led to the exponential growth of computing power.