I conclude that nuclear energy is the safest, most economical and environmentally clean. 我的结论是核能是最安全的, 也是最经济的,对环境造成的污染也是最小的. 出国英语口语25天快训
It's safest to keep a good distance behind in case the car in front suddenly stops. 最安全的办法是在后面保持相当一段距离,以防前面的汽车突然停车. 《简明英汉词典》