Question

PLEASE HELP!!!!! NEED THESE BY 3:00!!!!!!!!!!!!!!!!! SCIENCE Unit 5-6 Test: Sculpting Earth's Surface!!!!!!!!!

Answer 1

15. Groundwater is one of our most important natural resources. It provides us with much of the water that we use for drinking water, household uses, crop irrigation, and many other things. In fact, over 1/3 of Earth's population relies on groundwater for its needs, including 99% of the rural population in the U.S.

16. I dont know this one 

17. One type of cavern, known as solution caverns, are formed when large portions of limestone beneath the ground disintegrate and dissolve through the action of underground water. Solutional caves are the most frequently occurring caves and such caves form in rock that is soluble, such as limestone, but can also form in other rocks, including chalk,dolomite, marble, salt, and gypsum.