block and block [= chocka-block

Safe bind and safe find

2 atrioventricular block and complete atrioventricular block

BDCB Block Device Control Block

Block 36 and Block 38 in Oman

block and block

block by block relaxation operator

block by block transfer

block gage (gage block) (slip gage)

Block Xia 502 and Block Xia 509

block-and-block

block-by-block operation

block-by-block transmission

Building Block and Block Building

jewel block dasher block

plummer-block (plumber block)

V-block (Vee-block)

vee block (V-block)

a point of safe return