singly /ˈsɪŋɡlɪ/

• 1. 

  ADV If people do something singly, they each do it on their own, or do it one by one. 单独地; 一个接一个地 [ADV with v]

  例：

  They marched out singly or in pairs.

  他们一个一个地或成双成对地走出去。