You see, killer whales, who live at the top of the ocean food chain, used to prey on sperm and baleen whales. 虎鲸在海洋食物链占据最高层，它通常捕食抹香鲸和须鲸。 When these were no longer available, the killer whales were f...
Until recently, when scientists studied changes in open-ocean ecosystems, 直到最近，当科学家们在研究开放海洋生态系统的变化时， they looked at changes in the bottom of the food chain that gradually make their way to the top,...
However, for some POPs, even low levels can be dangerous because they resist break down. 但是，即使是相对低的污染浓度也可能是安全隐患，因为污染物无法分解， When they get into your body, they stick around, accumulating...
Yes, eating organic foods is a great way to reduce the amount of pollutants in your body, 选择有机食物大大减少了污染物进入体内， but you can't entirely escape pollution, no matter where you live. 但是无论你身在何处都无法一...
Researchers in the UK classified more than 2500 mammalian species as either solitary, socially monogamous, or as group living, which is when several breeding females live together. 英国的研究人员分类整理了在多个正处于孕期的雌性动...
One common explanation of social monogamy is that it's a result of females choosing mates based on the male's ability to provide for his off spring and protect them from being killed by hostile males or by predators. 关于社会一夫一妻制的常见...
In others, she made the kind of hand gesture most of us would make when saying that-a sort of banana-peeling mime that matches the content of the phrase. 但是，第二组志愿观看的视频中，她模仿默剧，做剥香蕉手势。 In a third...
You know, radio is a great thing. 要知道，收音机是伟大的发明。 Here I am! Flying high above the earth, but my voice is coming across just as if I were sitting right in front of you. 现在，我在演播厅，可是，我的声音让你觉...
That suggests that the trees were deciduous, meaning that they shed their leaves at the same time. 这说明树木会在每年的相同时间内落叶。 But fossilized wood from the region tells a different story. 但是该地区的木化石却又说明...
Dear A Moment of Science, I know that around 250 million years ago the Earth was a lot hotter than it is today. 亲爱的科学一刻，我知道大约在2.5亿年前，地球要比今天热的多的多。 So I'm wondering what that meant, exactly? 所...
If I was staring at something and looking really frightened, your brain would work harder to figure out if whatever is scaring me may also pose a danger to you. 如果我盯着一样东西看并受到惊吓，你的大脑就会努力找出，使我害怕...
You know how eye contact is a pretty important component of interacting with people, right? 我们都知道在与人交流时目光交流很重要。 So scientists recently tested this by measuring people's brain activity as they responded to picture...
The outermost is a layer of hardened, dead cells. 表层是一些坏死的硬细胞， This top layer is usually about twenty-five cells thick, and it constantly replaces itself as the outermost cells flake off to be replaced by new hardened, dead ce...
Most of us are familiar with calluses. 对于老茧，我们都很熟悉。 These extra-tough patches of skin are generally quite useful-we might even say handy-because they act likea kind of natural armor, 这些皮肤上突出的硬皮是很有用的...
The recordings lasted two minutes, but the effects on the fetuses' hearts went on for several minutes beyond the recordings. 此外，录音时间只有两分钟，但是胎儿心跳对此的反应却远不止两分钟。 That's pretty interesting! B...
