1) Orchids are one of the largest families of flowering plants, with over 25,000 species.

2) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

3) Chinese mythology, deeply intertwined with Chinese culture and history, includes deities such as the Jade Emperor, Guanyin, and the Monkey King (Sun Wukong). It incorporates elements of Taoism, Confucianism, and Buddhism and features legendary creatures like dragons, phoenixes, and Qilin.

4) The word "yesterday" contains three vowels: E, A, and A.