at time偶尔,
E.G
1.One expects healthy children to be mischievous at times.
健康的孩子有时很调皮,这是意料之中的.
to time
没听说过,from time to time,有时,不时,adv
on time
准时,
E.G
You should attend the meeting on time.你应该准时参加会议
in time及时
E.G
finish it in time ,及时完成