It's a pulsating star that swells and shrinks periodically.

它是颗脉动的恒星，地膨胀和收缩。

Lemmings periodically commit mass suicide, and no one knows just why!

旅鼠会地进行大规模自杀，但是没人知道究竟是为什么！

We'll be looking at various, innovative energy efforts periodically, starting with one underway in Scotland.

我们在地关注能源领域各种创新的努力，从苏在进行的个能源工作开始。

I remember the boats heaving periodically, on the huge gently rolling waves.

我记得船在波浪中地起伏。

In the middle of the night, your body actually wakes up periodically, in something called microarousals.

在午夜，你的身体会地醒来，这就是所谓的微觉醒。

The electrons that move along an alternating current, on the other hand, periodically and consistently change direction.

另方面，在交流电中移动的电子会地、持续地改变方向。

UNIDENTIFIED MALE: That's something we've seen in very small numbers periodically over the years.

这是我们多年来地看到的小部分现象。

Better to leave it on, and use something else to periodically block the light reliably and rapidly.

最好不要关灯，用别的东西地可靠而迅速地阻挡光线。

Since then, North Korea has gone back, periodically, to using threats to get more money and food.

自那时以来，朝鲜经常地利用威胁来换取更多金钱和食物。

Ebola is a highly infectious virus that has affected areas in Africa periodically over more than 40 years.

埃博拉病毒是种高度传染的病毒，40多年来地影响着非洲地区。

The best measure, they say, is the cyclically adjusted price-to-earnings ratio, or CAPE, developed by Yale economist Robert Shiller.

他们说，最好的衡量标准是地调整市盈率，即由耶鲁大学经济学家Robert Shiller提出的CAPE。

The grotesque grasshopper that relentlessly pulls time forward periodically winks at passersby.

怪诞的蚱蜢无情地把时间往前拉，地向路人眨眼。

Scientists know that volcanic eruptions have periodically cooled the climate.

科学家们知道，火山喷发地使气候变冷。

His hopes for the best had been but periodic interruptions to a chronic fear of the worst.

他对最好的希望只是地打断对最坏情况的长恐惧。

When the eggs hatch, the juvenile horseshoe crabs often stay near shore, periodically shedding their shells as they grow.

当卵孵化时，幼年马蹄蟹通常留在岸边，随着它们的生长地脱壳。

They come in cycles and it sounds like this deglobalisation period that we're in could rebound at some point.

它们地出现， 听起来我们所处的这个去全球化时可能会在某个时候反弹。

It tells our bodies when to wake up, eat and sleep in a cycle -- a series of activities that repeat themselves day after day.

它会地提示人体苏醒，进食，睡觉的时间——这些活动每天都会重复进行。

Alternating current, by way of contrast, periodically reverses and changes direction along a grid or system as its magnitude alternately reverses course.

相比之下，交流电随着其大小交替地改变方向，沿着电网或系统地反转和改变方向。

From time to time – " periodically, " we would say – stock markets crash, and the U.S. stock market crashed in 1903.

有时——我们会说“地” ——股市崩盘，美国股市在 1903 年崩盘。

The binary system periodically brightens by a huge amount partly because the larger star is being pulled out of its normal shape by the white dwarf's gravity.

这个双星系统会地变亮，亮度非常大。部分原因是较大的那颗恒星被那颗白矮星的引力拉扯出常形状。