Pregnant women may only eat four species of fish, and the elderly consume only other species.

怀孕的妇女或许仅能吃四种鱼，而老人只能享用剩余种类的鱼。

youdao

And just four species - wheat, maize, rice and potato - provide half of our energy from plants.

仅仅4个物种，即小麦、玉米、稻和马铃薯，就为我们提供了一半的植物源能量。

youdao

In these four species, scientists see considerable social complexity and individual distinction.

科学家们从这四个物种身上看到了相当显著的社会复杂性和个体差异。

youdao

But the report lists one hundred eight-four species that are considered in danger because of limited habitat, serious threats or falling populations.

VOA: special.2009.05.12

At depths of nearly four hundred meters, the researchers found the oldest examples of two species of coral.

VOA: special.2009.05.12

There are four kinds of echidnas: three species are long-nosed, while another has a short nose.

VOA: special.2009.07.07

The tests showed that, when untended by people, all four species of crop did badly.

ECONOMIST: Genetically modified weaklings | The

Here, humpback whales frolic for much of the winter months and four species of dolphin can be seen year-round.

BBC: Otherworldly Hawaii, for less

Researchers worked out the entire genetic code of four species of tapeworm parasite.

BBC: 'Weakness mining' for tapeworm drugs