Each driver must undergo a three-month probationary period before being allowed to operate independently.
Each driver must undergo a three-month probationary period before being allowed to operate independently.
在独立驾驶之前，每位驾驶员必须经过为期3个月的试用期。
Each driver must undergo a three-month probationary period before being allowed to operate independently.
在独立驾驶之前，每位驾驶员必须经过为期3个月的试用期。