Possible Clues:

• Diffusion through a semi-permeable membrane
• Fluid movement process
• The outsized doctor will get his little sister through with this
• Effortless learning procedure
• One way to get through a wall
• One way to learn by
• Passage of bodily fluid through porous partition
• So it's back to the doctor with your little sister; that way it'll get through
• Diffusion through porous barrier
• Diffusion of liquids