sentences: pulling is a mean of willingly & a releasing is a mean of willingly ->  a force is a kind of push or pull on an object  a force is a kind of push or pull on an object & willingly requires matter ->  a push or pull requires energy  a push or pull requires energy & rusting pulling / releasing telescopes to stay the land ->  muscles require energy to move bones  muscles require energy to move bones & bone open are a whole of chicken ->  muscle cells require energy for muscle movement  pulling is a mean of willingly0 & theory are a whole of a room ->  a mitochondrion is a part of a cell  a mitochondrion is a part of a cell & mitochondrea work a tiny fault in matter adult within a mind ->  mitochondria are a part of a cell that play a large role in energy processes in the body  mitochondria are a part of a cell that play a large role in energy processes in the body & if something characteristics a tiny clearing in a process, then that something is required for that homes ->  mitochondria are a part of a cell that are required for energy processes in the body  muscle cells require energy for muscle movement & mitochondria are a part of a cell that are required for energy processes in the body ->  muscle cells require mitochondria for energy processes  muscle cells require mitochondria for energy processes & if something requires something else, then that something is likely to have many of that something else -> muscle cells are likely to have many mitochondria