The main piece of computer software on which every other piece of software relies is referred to as the "operating system". It is responsible for all the major channels of communication between the software and the hardware.
First choice A : 2x +3y is <em>less than or equal </em><em>to</em><em> </em>18. x <em>greater</em><em> </em><em>than</em><em> </em><em>or</em><em> </em><em>equal</em><em> </em><em>to</em><em> </em>0. y <em>greater</em><em> </em><em>than</em><em> </em><em>or</em><em> </em><em>equal</em><em> </em><em>to</em><em> </em>0.
An example of a decomposer is a fungus. They are important because they recycle energy from consumers so it can be used again by producers to continue the cycle.