sentences: sand win transition contracting in sand & sand deposition seaweed sand win through unwind / land / people ->  soil erosion caused by water will cause grooves in soil  soil erosion caused by water will cause grooves in soil & squirrels is a mean of land ->  rainwater can cause grooves in soil  rainwater can cause grooves in soil & a savanna is made of sand -> rainwater can cause grooves in a riverbank