What is the normal pulse pressure?

Complete the missing words in the statements given below:
$(a)$ Plasma without clotting factors is called serum.
$(b)$ $.........$ and monocytes are phagocytic cells.
$(c)$ Eosinophils are associated with $.........$ reactions.
$(d)$ $.........$ ions play a significant role in clotting.
$(e)$ One can determine the heart beat rate by counting the number of $.........$ in an $ECG$.

What is represented by the $P$-wave in an $ECG$?

Select the correct option for $ECG$.

The $T$-wave in a normal $ECG$ represents . . . . . . .

$X-$ In $ECG,$ $P-$ wave represents the electrical excitation of the ventricle.
$Y -$ $QRS$ waves represent depolarization of atria.