Complete the sentences with the correct words

• Harmful
• diseases
• released
• threat
• grazed

1. [ ] pesticides sprayed on vegetables
   can have a really bad effect on our health.
2. Improved cleanliness helps to prevent the spread of [ ] .
3. The fire at the factory [ ] poisonous gases into the atmosphere.
4. Sea pollution is a terrible [ ] to sea creatures such as whales and dolphins.
5. Several sheep [ ] on the long grass in the field.