Subject: What happens to light as it passes through a translucent substance?

I am a teacher looking for a scientifically accurate explanation for
translucency for a grade 4 level. Definitions often say that translucent
substances don't let as much light through as a transparent substance. What does
that mean? Is the light being reflected, absorbed or scattered by the substance?
Why can't we see through a translucent substance? Additionally, some substances
seem to be very translucent while others are barely translucent. When does a
substance stop being translucent and become opaque? Are there varying levels of
translucency?

Re: What happens to light as it passes through a translucent substance?