单词	boundary-- fictitious
释义	boundary， fictitious假设边界
随便看	direction of propagation direction of recession direction of regeneration direction of relative movement direction of rolling direction of rotation direction of scanning direction of search direction of secondary engage direction of strata direction of taper direction of teeth direction of testing direction of the wind direction of tilt direction of time direction of traffics direction of twist direction of vibration direction of wave direction of wind direction on privacy and electronic communications direction operation direction operatoin direction opposite to that of traffics