1. Last year, Mandar did a week-long trek in Uganda, but he had to deal with altitude sickness, which is a condition caused by lack of oxygen at high altitudes.

2. Before you can learn to drive in the U.S., you need to get a learner's permit, which is a document that allows you to practice driving under certain conditions.

3. The rangers at the national park are responsible for maintaining the trails and making sure that visitors follow the rules.

4. Radyt just bought a new canteen, which is a container for carrying water, at the camping supply store. It holds more than two liters of water.

5. I didn't hire a porter, which is a person who carries your gear for you, for my hike through the Mountains of the Moon.

6. He has all the necessary gear for camping, such as a canteen, a good backpack, a compass and more.

7. The park rangers asked the campers to properly store their food so bears wouldn't be attracted to their campsite.

8. When Emge went skiing last year in Colorado, he had a slight problem with dehydration, which is when you don't drink enough water.

9. The doctor said Sansan was suffering from altitude sickness, which is a condition caused by lack of oxygen at high altitudes.

10. The national park is very well maintained. All of the marked trails are clear, so it is almost impossible to get lost.