Question

28. As far as possible dimensions should be given in one unit, preferably in
a) decimetres b) millimetres c) centimetres d) kilometres
29. The horizontal dimension is placed
the dimension line
a) on b) above c) below d) beyond
the dimension line​

Answer 1

Explanation:

28. d) Kilometer

29. d) Beyond

Answer 2

(28).As far as possible dimensions should be given in one unit, preferably in

millimetres.

"It is always preferred that the unit used for dimensions are mm (millimeters). Depending upon our need  or the size of the object, meters or centimeters can also be used."

HENCE, (B). millimeters is the correct option.

(29). The horizontal dimension is placed above the dimension line.

HENCE, (b). above is the correct option.