Read the following words and phrases and their definitions.
to be beyond help -
to be at a point where nothing can be done to make things better
bedrock - the solid rock that lies under the surface of the ground
worn away by erosion - gradually destroyed by natural forces
limestone - a whitish-coloured rock
susceptible - easily affected, influenced or harmed by something
cracks and crevices - a narrow openings in a hard surface, especially in rock
pumice - a gray stone that comes from volcanoes and is full of small holes
to erode - to be gradually destroyed by natural forces such as water, wind or ice
sewer pipes - pipes that are usually underground and that are used to carry off water and such
in the blink of an eye - very quickly
to detect - to discover or notice