$1)(0\mathrm{.}5$ Marks$)$ Datums establish the

from which the location or geometric characteristic of features of a part are established.

$2)(1$ Mark$)$ A datum reference frame consists of three mutually perpendicular and three mutually perpendicular at the intersection of those planes.

$3)(0\mathrm{.}5$ Marks$)$ Datum feature letters need not be in order.

$4)(0\mathrm{.}5$ Marks$)$ The primary datum feature controls the of the part.

$5)(1$ Mark$)$ Datum features must be identified with

or and specified in a feature control frame.