Earth's Changing Surface

4. The ______ is all of the water on the Earth, including frozen forms.
5. underground opening that can form when acidic groundwater dissolves limestone
7. Water may take different amounts of time to _____ through the ground.
10. mound formed when windblown sediments pile up behind and obstacle
11. substance with a pH lower than 7
14. During ____ sediments get carried to the bottom of the ocean.
15. There are many different types of ____. Some are edible and some are not
17. There are many types of rocks and minerals that make up the ____ of the Earth.
19. A satellite was launched into orbit to monitor melting ___ in the Artic.
20. Because of ____, the beach has decreased in size.

1. living things and things that support life
2. all frozen water on the Earth
3. _____ is an important source of drinking water.
6. landform that forms from the deposition of sediment at the mouth of a river
8. layer of permeable rock that allows water to flow through
9. ______ is important for plants because water soaks into the soil.
12. the gases that surround the Earth
13. the loose top layer of the Earth's surface made of weathered rock and organic matter
16. The rock was ____ so water could easily move through it.
18. substance with a pH higher than 7