There is always a lifeguard to ensure that no one comes to any harm
总是有一个救生员在场以确保无人受到伤害。
This month millions of American kids can forget about classroom bells and set off for grandparents' homes, sleep-away camps and lifeguard stands ．
这个月，数以百万的.美国小孩可以忘掉上课铃声，出发前往祖父母家、外宿营地以及沙滩上的救生员站。
Don't swim unless there is a lifeguard on duty.
除非有救生员值班,否则不要游泳。
Do you think I can become a lifeguard one day?
你觉得我会成为一名保镖吗？
Research and Analysis on the Actuality of Lifeguard of Mass Swimming in China
我国大众游泳救生员现状调查与分析