Match the pump types in Group I with their key components in Group II.
\[
\begin{array}{|c|c|}
\hline
Group I & Group II
\hline
(P) \ \text{Centrifugal pumps} & (1) \ \text{Piston rod}
(Q) \ \text{Reciprocating pumps} & (2) \ \text{Impeller}
(R) \ \text{Rotary pumps} & (3) \ \text{Gear}
(S) \ \text{Impulse pumps} & (4) \ \text{Eductor pipe}
& (5) \ \text{Hydraulic ram}
\hline
\end{array}
\]