  The de Broglie-Bohm quantum trajectories are found in analytically closed
forms for the eigenstates and the coherent state of the Lewis-Riesenfeld (LR)
invariant of a time-dependent harmonic oscillator. It is also shown that an
eigenstate (a coherent state) of an invariant can be interpreted as squeezed
states obtained by squeezing an eigenstate (a coherent state) of another
invariant. This provides ways for a whole description of squeezed states.
