The changes can be extremely subtle: something that feels internally like a rock, for example, may suddenly seem to melt into warm liquid.
(The changes; can be; extremely subtle) (something that feels internally like a rock; may seem; T:suddenly) (something that feels internally like a rock; to melt; )
The changes something that feels internally like a rock something that feels internally like a rock
can be may seem to melt
extremely subtle
T:suddenly