A line used as both sterile and maintaining line
agonic line {agonic line of no declination}
Dual purpose line with nucleic male sterile line
Fault Cutoff Line Allan Line
Male sterility line and maintainer line
velocity line of arc line short band
1st Class or 2nd Class Control
angle Class Ⅱand skeletal class I malocclusion
Class Ⅰ and Class Ⅱ highways
Class A and class B infectious diseases
0-1 symmetric matrix of positive line
±500 kV ultrahigh voltage DC transmission line
1 000 kV AC power transmission line