Which of the following elements does not show allotropy?

$CFCl_3$ is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen?

Identify the correct gland on the basis of the following characteristics:
$(I)$ It is located on the dorsal side of the forebrain.
$(II)$ It plays a very important role in the regulation of the $24$-hour rhythm of our body.
$(III)$ It helps in maintaining the body temperature.
$(IV)$ Its hormone influences metabolism as well as defense capability.

If $f(x) = \int_{-1}^{x} |t| \, dt$, then for any $x \geq 0$, $f(x)$ is equal to

Among the following compounds,which one is not responsible for the depletion of the ozone layer?