There are more than four items but the four basic things are mother board/CPU, power supply, hard drive, and RAM. Of course you would need a case to hold it all and various cards depending on what the motherboard has on it. (sound, video, USB, firewire)
Data Communication is the transmission of data (text, voice, etc) from one computer to another (or to a peripheral device). The four things needed are a sender, a receiver, a channel and a protocol.
Four items that make a protein are carbon, hydrogen, nitrogen and oxygen. These are the four items that make up an amino acid. Protein is made up of amino acids.
Nucleotides Four nucleotides are needed to make a DNA molecule.
A wire and a magnet
a computer
they made items the colonists needed?
Technology
Technology
Some of the main items that form a computer include the monitor, keyboard, hard drive and the motherboard. These same components create laptops, as well.
Four and half
Sometimes resetting a cars computer is needed to make it work better. A cars computer can be reset by a dealership mechanic.
Omni Staff AND Talisman Stick from Rc Guild.