In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

Q: The thoracic diaphragm , or simply the diaphragm , is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity .

A: The diaphragm is a muscle that is at the bottom of the ribcage of mammals .
****
Q: In most cases , the municipalities are the smallest administrative subdivisions of Belgium , but in municipalities with more than 100,000 inhabitants , on the initiative of the local council , sub-municipal administrative entities with elected councils may be created .

A: Usually , municipalities are the smallest subdivisions of Belgium , but in municipalities with more than 100,000 people living there , they get divided into districts .
****
Q: The degree of cementation in Portland stone is such that the stone is sufficiently well cemented to allow it to resist weathering , but not so well cemented that it ca n't be readily worked ( cut and carved ) by masons .

A:
Portland stone is hard enough to resist weathering but soft enough to be worked ( cut and carved ) by stonemasons .
****