The $mesothelium$ is:

Epithelial tissue performs which of the following functions?

Match the terms given in column-$I$ with their feature given in column-$II$ and choose the correct option.

Column-$I$ (Terms)	Column-$II$ (Features)
$A$. Exocrine gland	$I$. They help to stop substances from leaking across a tissue
$B$. Endocrine gland	$II$. Hormones are secreted directly into the fluid bathing the gland
$C$. Tight junctions	$III$. They perform cementing to keep neighbouring cells together
$D$. Adhering junctions	$IV$. Secretes mucus,saliva,earwax,oil,milk,digestive enzymes and other cell products

Read the following statements and answer the question.
$(i)$ It is made of a single thin layer of flattened cells with irregular boundaries.
$(ii)$ They are found in the walls of blood vessels and air sacs of lungs.
$(iii)$ They are involved in functions like forming a diffusion boundary.
Which of the following characteristics of tissue is being described by the above statements?

In which one of the following preparations,cell junctions come across most frequently?

In four healthy individuals in their $20$s,if the following cells are damaged or destroyed due to injury,which of these cells are most likely to be replaced by new cells?