86) The thickness of five-ply sheet varies from

• (a) 3 to 6 mm
• (b) 6 to 9 mm
• (c) 9 to 16 mm
• (d) 16 to 20 mm

87) The thickness of lamin boards vary from

• (a) 5 to 12 mm
• (b) 12 to 15 mm
• (c) 12 to 25 mm
• (d) 25 to 30 mm

88) The wood generally used for railway sleepers is

• (a) mango
• (b) kail
• (c) babul
• (d) deodar

89) The chief ingredient of a paint is

• (a) alcohol
• (b) drier
• (c) oil
• (d) pigment

90) The liquid medium used in oil paints is

• (a) thinner
• (b) alcohol
• (c) linseed oil
• (d) turpentine