Onetheory is that it is a spy plane, designed to catch savvy targets that know how to go to ground when spy satellites—which have predictable orbits—are overhead.
这些精明的目标发现间谍卫星（有可预见的轨道）位临上空时，能够知道如何隐蔽自己。
2
The geometrical theory of diffraction (GTD) has been used to calculate the Roll-Plane (Equatorial-Plane) radiation of the one and two vertical monopole elements on the base of the cone.
本文应用几何绕射理论(GTD)，计算了圆锥底上一元和二元垂直单振子滚动面(赤道面)的辐射图。
3
One of those pieces – a wing flap found on a shore in Tanzania – seemed to confirm the theory that no one was at the controls of the plane in its final moments.