An
oyster on the ocean floor opened wide its shell. As its valves flushed
seawater through, the oyster picked out minute particles of food.
Suddenly a large fish nearby stirred up a cloud of sand and silt with a flip of its tail.
Sand.
Oh, how the oyster disliked sand! It was so rough that it made life
very unpleasant for the oyster whenever any got inside its shell.
Quickly
the oyster slammed its shell shut, but it was too late. One hard gritty
grain of sand had gotten in and became lodged between the oyster’s
flesh and shell.