C. Complete the sentences with the Present Simple Passive or the Past Simple Passive of the verbs in brackets.
1. Research has shown that these rocks ____________ (not form) four million years ago but much earlier than that.
2. Bamboo plants ____________ (grow) in many Asian countries.
3. These sponges __________ (collect) from a reef near the coast by some divers yesterday.
4. After the war my grandad __________ (give) a medal.
5. The resort on the island _________ (visit) by hundreds of tourists vevry year.
6. Bamboo shoots are young bamboo plants and __________ (eat) in many places around the world.