The right answer is Joints (or ligaments more precisely).
Muscle is the contractile structure that produces strength. It has components that allow it to be shortened to create what is called a muscle contraction.
The joint is junction of two parts of the skeleton allowing them relative mobility.
The ligament is an elastic structure that stabilizes the joints. It therefore attaches from one bone to another.
Our body needs some kinds of bacteria to maintain a balanced and healthy state. for example, our bodies need Lactobacillus acidophilus to create lactic acid which is the acid in our stomachs/intestines. without it, we wouldnt be able to properly digest our food.
there are some cases in which bacteria can be really harmful however like salmonella which, odviously isnt ideal for our bodies. even good bacteria can hurt us if we end up with to much of it.
this isnt a super detailed explaination but i hope it helped!
You can decrease your fat by doing exercise
