4. Check your understanding: multiple choice
1. Modern explorers use compasses and 
satellite phones and GPS 2. Ed often didn’t have enough food 
3. Erik takes groups of blind people up mountains .
4.  Ed used technology to contact local people.
5. Gerlinde supports a charity that helps children .
6. Gerlinde  hasn’t done a long-distance bike ride.
7. Ed  had to look out for wild animals.
8. Gerlinde had to go slowly because there wasn’t much oxygen.