$25.$ True$/$False: The drift flux model's drift velocity is the same regardless of flow regime.

$26.$ True$/$False: Temperature variations do not affect the performance of fluidized bed reactors.

$27.$ True$/$False: Dense phase pneumatic conveying is characterized by higher velocities than dilute phase conveying.

$28.$ True$/$False: The gas holdup in a bubble column reactor decreases with increasing gas flow rate.