English

2. a large natural elevation of the earth's surface rising abruptly from the surrounding level; a large steep hill.
5. the basic or inherent features, character, or qualities of something.
7. is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products
8. them to realize the nature of their problems"
10. horizontal plane"
11. is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance
12. a global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols.

1. cheeks were pressed together as they danced"
3. a flightless swift-running African bird with a long neck, long legs, and two toes on each foot. It is the largest living bird, with males reaching a height of up to 2.75 m.
4. star round which the earth orbits.
6. move rhythmically to music, typically following a set sequence of steps.
8. guide is also available on the internet"
9. a flat surface on which a straight line joining any two points on it would wholly lie.
10. set off down the mountain"