短语词组短語LEAP SECOND PENDING STATUS 閏秒等待狀態positive leap second [天]正閏秒negative leap second [天]負閏秒leap second adjustment 閏秒調整second leap -over 二次跨越a second leap 二次飛躍the second leap 第二個飛躍the second historical leap 第二次歷史性飛躍 返回 leap second