cylinder block pan rail
shortened rail；standard shortened rail；fabricated short rail used on curves；standard curtailed rail
block and block [= chocka-block
2 atrioventricular block and complete atrioventricular block
BDCB Block Device Control Block
Block 36 and Block 38 in Oman
block by block relaxation operator
block by block transfer
block gage (gage block) (slip gage)
Block Xia 502 and Block Xia 509
block-by-block operation
block-by-block transmission
Building Block and Block Building
jewel block dasher block
plummer-block (plumber block)