Questions

The law of conservation of energy is a law of science which states that energy can neither be created nor destroyed - only converted from one form of energy to another.

In 1842, Julius Robert Mayer discovered the Law of Conservation of Energy.

Therefore the answer for What travels around the world but stays in one spot is STAMP or any other thing that acts as a stamp does.

Ex. the letter in the envelope etc...

Since, Several things have the possibility, but the word travel evokes that it would move. 

Sound intensity or level is measured by a unit called a decibel. An 85 decibel noise level is not a safe standard for the public.

Hence, Acceptable noise level for human ear is less than 85 db.

IRQ-0 is the system timer commonly use in all computers. In a computer, IRQ is an interrupt request which acts as a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead.

Oligopoly is market structure where a small number of large firms are there. Oligopolistic industries are characterized by a few dominant firms and substantial entry barriers.

Let initial investment of A = x
Ratio of profit A : B : C = 12 × x : 6×4500 :4×4500
A :B:C = x : 2250: 1500
Now ATQx/(x+2250+1500) = 4900/10000
solving this we get,x ≈ Rs 3600

It is using a router to answer ARP requests. This will be done when the originating host believes that a destination is local, when in fact is lies beyond router.