приховане випробування
surreptitious movement
surreptitious chemical weapons capability
surreptitious eavesdropping
surreptitious entry
surreptitious listening
surreptitious listening device
surreptitious method
surreptitious operation
surreptitious smoking
psychological testing
hardware redundancy testing
barrel-testing rod
block testing stand
hydraulic testing equipment
incremental proof testing
bench testing program
bond testing
fatigue testing machine
fault testing
friction testing
functional testing
high-stress testing
impact testing
in-service testing
loads testing
marginal testing
mechanical shock testing
static structure testing
structure testing machine
tensile fatigue testing
testing
tunnel free-flight model testing