As scheduled, the communications satellite went into _____ round

As scheduled, the communications satellite went into _____ round the earth.
A、circle
B、orbit
C、path
D、course
【正确答案】：B
【题目解析】：circle 循环；orbit 轨道；path 道路；course 科目句意：按照预定计划，这颗通信卫星进入了环绕地球的轨道。