64. The asbestos cement sewers are
A. light in weight
B. not structurally strong to bear large compressive stress
C. susceptible to corrosion by sulphuric acid
D. All the above.

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65. The asbestos cement pipes are generally laid
A. horizontally
B. vertically
C. at an angle of 30?
D. at an angle of 60?,

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66.  Large diameter sewers subjected to external pressure alone, are reinforced
A. near the inner surface of the pipe
B. near the outer surface of the pipe
C. both A and B
D. with elliptical cage

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67. Hume steel pipes are
A. steel pipes
B. R.C.C. pipes
C. steel shell coated from inside with cement mortar
D. both B and C

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68.  Stoneware sewers are available in size
A. 10 cm
B. 15 cm
C. 20 cm
D. all the above.

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69. Pick up the incorrect size of stone ware sewers
A. 52.5 cm
B. 67.5 cm
C. 82.5 cm
D. 90 cm

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70. The stone ware sewers
A. are used for carrying sewage and drainage from houses
B. are manufactured from clays and shales
C. after casting are dried and burnt at temperature 150?C, 700?C and 1200?C
D. all the above.

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