A. do not require bevelling
B. should be bevelled to a single-V or U-groove
C. should have a double-V or U-groove on one side
D. should have a double-V or U-groove on both sides
A. do not require bevelling
B. should be bevelled to a single-V or U-groove
C. should have a double-V or U-groove on one side
D. should have a double-V or U-groove on both sides