The Great Wall in China was built / were built / built / build many centuries ago.
I think collector / collecting / collects / collection coins is very interesting.
Ruby was late for class yesterday, and / so / but / or / because she missed the first bus.
The weather is cold today, and / so / but / or / because you should put on a coat.
He has a toothache, and / so / but / or / because he still eats lots of sweets and cakes.
You should bring an umbrella, and / so / but / or / because you will be wet.
Take up a new hobby, and / so / but / or / because you’ll have some new friends.