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1. glaciers: It is it assumed that glaciers moves slowly, but occasionally they have surges and move up to 50 times faster than normal.
2. salinity: The Dead Sea is famous for the salinity of its water.
3. humidity: The humidity in tropical areas can make you very tired.
4. kilometres / kilometers: The oceans can reach depths of eleven kilometres in places.
5 pressure: Altitude sickness is due to a reduction in air pressure.
6. evaporation: Rain is mainly caused by evaporation from the oceans.
7. environment: We need to look after the environment around us.
8. biology: Biology is a branch of the natural sciences.
9. brightness: Our perception of the brightness of the sun changes with the seasons.
