Question

Solids are generally non compressible why can sponge be readily compressed?

Answer 1

it is because sponge have minute holes between them, air if filled up in the holes, when we squeeze the sponge the air molecules goes out and it's space is taken up by the molecules of matter. But still a piece sponge is a solid.

Since on compressing sponge the sponge is squeezed but after a minute or two it regains its shape and mass , therefore sponge can be considered solid though it has property of compression.