We did a three-minute safetystop, then surfaced at the 30-minute mark.
我们昨晚3分钟的安全停留，在第30分钟的时候浮出海面。
2
In the process of decline in the use of photoelectric sensor to detect a robot ground safetystop.
在下降的过程中利用光电传感器检测地面来实现机器人的安全停止。
3
Rong Sheng from the school's safety department said, "In the past, our school safety guards had to stand in the middle of the road after school to stop the cars."