second sound

• 第二声

second sound的用法和样例：

例句

1. As the second bell rang in the hallway, I ran to the door of the classroom.
   走廊响起第二声钟响时，我才跑到教室门口。
2. A second long whistle shall bring the backstroke and medley relay swimmer immediately to the starting position.
   总裁判应用第二声长哨示意仰泳或混合泳接力的仰泳运动员立即就位。