зворотний хід поршня
back-to-back circuit
back-to-back connection
back-to-back radio stations
back-to-back relay
four-cycle / four-stroke
power stroke
recoil stroke
stroke
ascending stroke
bottom end of stroke
expansion stroke
four-stroke cycle
impact stroke
operating rod stroke
recovery stroke
shock strut stroke
spring stroke
compression stroke
exhaust stroke
intake stroke
four-stroke engine
two-stroke engine
fell stroke
back-up fire control
back-up system
cut back co-operation
I read back
play back kit
pull back
push back
read back
reverse engineering ( back- wards engineering)