at intervals

It snowed at intervals this week.

这星期不时下雪。

These cars are put at intervals of three meters.

这些车每隔三米放辆。

Flaming torches were positioned at intervals along the terrace.

沿台阶每隔段距离布置有燃烧着的。

The UIE hold a large scale international academical congress at intervals of four years.

要国际电热会(UIE)每隔4年举大规模国际性的电热学术会议。