1·Periodic checks are carried out on the equipment.
设备定期进行检查。
—— 《牛津词典》
2·Melanomas are more common if you have periodic intense exposure to the sun.
如果你定期暴露在强烈的阳光照射下，黑色素瘤会更常见。
3·By isolating organisms completely from external periodic cues, biologists learned that organisms have internal clocks.
通过将生物体与外部的周期信号完全隔离，生物学家了解到生物体有内部的生物钟。
4·Online time has doubled since 2006, and social media use has moved from a periodic activity to a daily one in the same period.
自2006年以来，上网时间翻了一番，而与此同时，社交媒体的使用也已经从定期活动变成了日常活动。
5·In places, the water table is declining at a rate of a meter a year, necessitating the periodic deepening of wells and the use of ever-more-powerful pumps.
在一些地方，水位正以每年一米的速度下降，需要定期加深井并使用更强大的水泵。
6·Periodic checks are taken to ensure that high standards are maintained.
进行周期性检查以确保高标准得以维持。
—— 《柯林斯英汉双解大词典》
7·So is my version of the periodic table wrong?
那么我的元素周期表是错的吗？
8·Does that explain why it was missing in the periodic table?
这能解释为什么它在元素周期表中缺失了吗？
9·This kind of periodic orbit is only a phase in a comet's life.
这种周期性轨道只是彗星生命中的一个阶段。
10·Periodic changes in Earth's orbit could affect Earth's climate.
地球轨道的周期性变化会影响地球的气候。