1. Vocabulary. Complete the sentences with the correct words or phrases: terrifying, research station, compete, crashed into, special offer, blizzard, scare off threatened, greenhouse gas, volcano surfing, under threat, protective, unpredictable, stunning scenery, footpath 1. The hikers got lost when a sudden ______ covered all the trails in deep snow. 2. Scientists at the Arctic ______ study the effects of climate change on polar bears. 3. Many animal species are ______ because their natural habitats are disappearing. 4. ______ is an extreme sport where you slide down an active volcano on a board. 5. Wear ______ gloves and goggles to keep your hands and eyes safe from the hot ash. 6. Athletes from different countries will ______ in the winter sports competition. 7. The national park is famous for its ______, including mountains, lakes and waterfalls. 8. We followed the narrow ______ through the forest to reach the waterfall. 9. The hotel had a ______: stay two nights and get the third night free. 10. The weather on the mountain is very ______ - it can change from sunny to stormy in an hour. 11. Polar bears are ______ because the melting ice makes it hard for them to hunt. 12. Cars and factories release a lot of ______ into the atmosphere. 13. The dog ran towards the stranger to ______ him ______ from the garden. 14. The spaceship ______ the satellite, causing serious damage to both. 15. The horror movie was so ______ that I couldn't sleep after watching it.