at a time
US /æt ə taɪm/
UK /æt ə taɪm/
成语
一次, 每次
separately in the specified groups or numbers; during one individual period of time
示例:
•
Please go up the stairs two at a time.
请一次跨两级台阶上楼。
•
He can only do one thing at a time.
他一次只能做一件事。