Questions

It is the letter 'e', that is the first on earth, the second in heaven.

It appears twice in a week, that appears once in a year.

A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain.

To make steel, iron ore is first mined from the ground. It is then smelted in blast furnaces where the impurities are removed and carbon is added.

In simple, steel is iron alloyed with carbon, usually 0 - 2%.

A yellow element that stinks when burned is Sulphur.