单项选择题
A.two red lights B.one green light C.one white light D.one amber light
A line of position from a celestial observation is a se...
单项选择题A line of position from a celestial observation is a segment of a （）.
A.circle of equal altitude B.parallel of declination C.parallel of altitude D.vertical circle
A line of position derived from a loran reading is a se...
单项选择题A line of position derived from a loran reading is a section of a(n) （）.
A.straight line B.arc C.parabola D.hyperbola
A light used to signal passing intentions must be an （）...
单项选择题A light used to signal passing intentions must be an （）.
A.all-round yellow light only B.all-round white light only C.all-round blue light only D.alternating red and yellow light
