是ata time还是fora time

1.at a time

at a time[简明英汉词典]

依次,逐一,每次

for a time

for a time[简明英汉词典]

短时间内,暂且

2.by the side在旁边

in the side在一侧

on the side[简明英汉词典]

①〈非正〉作为兼职〔副业〕 ② 暗地里,秘密地

at the side在一边

at the side of与……相比,在……的旁边