If you plan to remove several components from the computer, it is best to save a back up files just so some files won't be lost and if you have ever corrupted your file. Another thing is to safely turn off your computer and have yourself provide pictures or to remember the cables that are placed in each switch before having to remove several components.
Answer:
Ticks, flies, mosquitoes, and fleas.
Explanation:
The answer is a simple radial nervous system.
Echinoderms do not have brains. Around their mouth, they have central rings from which nerves radially run into arms and along the body. Movement is controlled by the branches of those radial nerves.
