Fill in the given words

• supply
• reefs
• protect
• covers
• survival

1. Harmful chemicals have poisoned the city's water
   [ ] .
2. There are lots of colourful coral [ ]
   in the sea.
3. We should all make an effort to [ ]
   endangered animals.
4. Water [ ] most of the Earth's surface.
5. Overfishing is endangering the [ ]
   of many sea creatures.