projectile motion

例句：

1. 1. The projectilemotion of the bullet is a crucial factorin its trajectory.
   子弹的投射运动是其轨迹的关键因素。
2. 2. The ballistic missiles were launched from a secret base inthe desert.
   秘密基地发射了弹道导弹。
3. 3. The ballistic flight of the spacecraft was recorded by the ground control.
   航天飞机的弹道飞行被地面控制记录。