单项选择题
Radar is not only to obtain（），but also to measure their distance away from you.
A.brightness of objects B.color of targets C.shape of targets D.bearing of objects
单项选择题 Most GPS receivers use the doppler shift of the carrier phase to compute（）.
单项选择题 Magnets in the binnacles of magnetic compasses are used to reduce the effect of（）.
单项选择题 It may be found that，in certain circumstances，Radar Beacon can cause unwanted interference particularly（）.
