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

2) 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.

3) The national animal of Australia is the kangaroo.

4) In Chinese mythology, the Dragon Boat Festival (also known as Duanwu Festival) is celebrated to honor Qu Yuan, a poet and statesman of ancient China. It involves dragon boat races, eating sticky rice dumplings (zongzi), and performing rituals to ward off evil spirits and protect against diseases.