skeletal system and the muscular system,
Muscles are attached to the skeleton and work assuming that the skeleton is there; for example, there is no muscle that makes sure you don't bend the middle of your arm, as it's stable because there is a bone in it. Basically, the skeleton is a scaffolding for the muscles.
the skeletal system and the nervous system,
Many nerves run along the skeleton, or even inside the bones, and the bones protect the nerves; for example in the spinal cord
the muscular system and the nervous system.
The Nervous system controls the muscles; it sends the muscles commands
To say no and if possible avoid those people or leave
riding a bicycle without your helmet
Heat the pan (and oil). In order to brown, rather than steam, the pan needs to be hot. Adding oil is optional but recommended for better browning.
Add the meat to the pan and break it into large pieces. Use a wooden spoon, fish spatula, or other sturdy spatula to break the meat up into large pieces in the pan. Let it brown for several minutes.
Break the beef into smaller pieces as it cooks. As the beef begins to brown, continue to break the meat into smaller and smaller pieces.
Cook until browned (and try not to stir). Try not to stir the beef too much; just stir occasionally until all of the beef is browned.
