standby

中英例句：

1. A special team of police were kept on standby during the time of violence.
   在發生暴亂期間，經常有一支警察特別小分隊處於整裝待命狀態。

英文解釋：

名詞 standby:

1. something that can be relied on when needed
2. an actor able to replace a regular performer when required
   同義詞：understudy

形容詞 standby:

1. ready for emergency use

詞型變化：