ひとりずつ

ひとりずつ【一人宛】

one by one; one at a time; one after another; 〔順次〕 in turn. [⇒ひとりひとり]

●ひとりずつ入ってください. Please go in one at a time.

・彼らはひとりずつ検査された. They were examined [underwent inspection] one by one [in turn]