Supposed*
You had a grammatical error and I had to fix it considering you’re an English teacher.
Cornerstone for me is a 7/10 and the other one a for sure 9/10 :)
1. Most people take a plane to Sydney from San Francisco, so they don’t know about the pollution in the ocean.
2. The work was tiring and the crew needed to take a break and relax sometimes.
3. The sun was shining and the sea was calm, so we went small boat fishing.
4. Children learn to think in teams, that when some people play in matches they work well.
5. The number of visitors of Canada’s national parks is getting lower every year.
