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

它是一的恒星，周期性地膨胀和收缩。

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

我记得船在波浪中周期性地起伏。

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

旅鼠会周期性地进行大规模自杀，但是没人知道究竟是为什么！

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

这是我们多年来周期性地看到的一小部分现象。

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

最好不要关灯，用别的东西周期性地可靠而迅速地阻挡光线。

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

在午夜，你的身体会周期性地醒来，这就是所的微觉醒。

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

自那时以来，朝鲜经常周期性地利用威胁来换取更多金钱和食物。

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

我们正在周期性地关注能源领域各种创新性的努力，从苏格兰正在进行的一个能源工作开始。

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

另一方面，在交流电中移的电子会周期性地、持续地改变方向。

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

埃博拉病毒是一种高度传染性的病毒，40多年来周期性地影响着非洲地区。

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

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

Scientists know that volcanic eruptions have periodically cooled the climate.

科学家们知道，火山喷发周期性地使气候变冷。

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，周期性地向路人眨眼。

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

对最好的希望只是周期性地打断对最坏情况的长期恐惧。

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，随着它们的生长周期性地脱壳。

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

它们周期性地出现， 听起来我们所处的这个去全球化时期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.

它会周期性地提示人体苏醒，进食，睡觉的时间——这些活每天都会重复进行。

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，沿着电网或系统周期性地反转和改变方向。

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“周期性地” ——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.

这个双星系统会周期性地变亮，亮度非常大。部分原因是较大的那恒星被那白矮星的引力拉扯出正常形状。