单项选择题
A radar range to a small，charted object such as a light will provide a line of position in which form?（）.
A.Straight line B.Arc C.Parabola D.Hyperbola
单项选择题 A radar display which is oriented，so that north is always at the top of the screen，is called a(n)（）.
单项选择题 A radar display in which North is always at the top of the screen is a(n)（）.
单项选择题 A radar contact will remain stationary on a relative motion radar display only when it is（）.
