Lava slowly filled _________ that were created by impacts of massive asteroids more than three billion years ago.
bowls
tunnels
basins
holes
Thick layers of _________ can build up in rivers and lakes.
fish
mud
sediment
water
The metal gate __________ the cars from entering the parking lot.
prevented
allowed
broke
turned
A man at the store ________________ how to use the sharp knives that were for sale.
demonstrated
told
copied
tested
_________ occurs in rivers when rocks are worn away by the moving water.
Erosion
Settling
Mud
Irritation
That is ____________ ink, so the stain will never go away.
tough
dry
permanent
blue
We hiked up the mountain and walked along the cold ice of the _________.
refrigerator
island
ground
glacier
___________ can turn large mountains into small hills over time.
Sandpaper
Weathering
Bacteria
Friction
The healthy tree withered and ___________ because bugs had eaten away the bark.
fell down
deteriorated
stretched
died
This ice __________ was created by years of water dripping down and freezing.
formation
sculpture
icicle
house