1) The Amazon rainforest produces more than 20% of the world's oxygen.

2) The development of blockchain technology, first introduced in 2008 with the creation of Bitcoin, has enabled secure and decentralized digital transactions and led to the emergence of cryptocurrencies.

3) The Serengeti National Park, located in Tanzania and extending into Kenya, is renowned for its vast savannahs, diverse wildlife, and the annual wildebeest migration. It is a UNESCO World Heritage site and a popular destination for safari enthusiasts and nature lovers.

4) The Industrial Revolution led to significant urbanization, as people migrated from rural areas to cities in search of employment in factories.