Excess of alumina in brick earth makes the brick______________?
A. Impermeable
B. Brittle and weak
C. To lose cohesion
D. To crack and warp on drying
The age of a tree can be known by examining_________________?
A. Cambium layer
B. Annular rings
C. Medullary rays
D. Heart wood
The main function of alumina in brick earth is_______________?
A. To impart plasticity
B. To make the brick durable
C. To prevent shrinkage
D. To make the brick impermeable
First class timber has an average life of_____________?
A. Less than one year
B. 1 to 5 years
C. 5 to 10 years
D. More than 10 years