Sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by groundwater circulating through them. As the rock dissolves, spaces and caverns develop underground.
Sinkholes are formed when the land surface above collapses or sinks into the cavities or when surface material is carried downward into the voids. Drought, along with resulting high groundwater withdrawals, can make conditions favorable for sinkholes to form.
Answer:
That's more than 275 million stars per day in the observable universe. Stars keep themselves fueled. They fuse elements together to make new elements. ... Once the star runs out of hydrogen, the helium atoms fuse together to make carbon.
Answer:
B. toward the center of the earth
