water. Humans can live for weeks without food but only a few days without water, so people in deserts spend much time in search of this most 3. ______ of all re- sources. Women of the Tubu tribe, for exam- ple, guide their camel caravans for days across the 4. ______ sands of the Sa- hara. They travel across the Sahara and back 5. ______ to buy salt and dates at market. On the way, they must not miss small wells. In South America's Atacama Desert, local people are very 6. ______: they get water by gathering the morning dew! 7. Read the text and choose the correct answer. Ash Dykes, 23 years old, spent 78 days crossing Mon- golia — one of the world's most desolate countries. The young adventurer has become the first person to walk 2,400 km 1. ______! As he passed through the Altai Mountains and the hot Gobi Desert, he 2. ______ known to locals as the "lonely snow leopard". Mr. Dykes dragged a 120 kg home made trailer which carried his food, water and camping 3. ______ He completed 55 km in 14 hours 4. ______ his longest day.