I like to move back and forth on black sock went i am wiggled
The particles in a solid move back and forth in place.
"Oscillate" means to move back and forth in a regular rhythm.
the particles in a surface water move back- and- forth only.
solids
solid
back and forth?
solid
solids
move back and forth in a circuit. :)
The planets orbit AROUND the sun, so technically not back and forth.
move your hand back and forth!
slither back and forth horizontally