In other words, it's not certain which came first: the health benefits of red wine, or that wine drinkers are healthy people.

换句话讲，很难判断喝葡萄酒的人更加健康是因为葡萄酒对人身体的好处，还是因为喝葡萄酒的人本身更加健康。

youdao

The relationship between black holes and their host galaxies poses a chicken-and-egg conundrum for astronomers, long curious about which came first.

黑洞和其所在的星系之间的关系就像是天文学家的先有鸡还是先有蛋的谜题，他们已经困惑哪个在先很久了。

youdao

For example, she"never knew which came first, the Greeks or the Romans."

例如有这样一桩有趣的事……「她永远弄不清楚，是先有希腊，还是先有罗马。」

youdao

It has a name which is the first name of the husband or the wife or the town where they came from -- Lois,Tony's,Estelle's,or Maria's, or the Calaberian or the Belonia.

VOA: special.2010.08.28

When the uncertainty gets that big, you don't know which came first.

当不确定度到那么大的数值时，你不知道谁是第一个到达的。

麻省理工公开课 - 固态化学导论课程节选

But even after that, even after our first two records which came out in nineteen seventy, our only initial goal was to make one record which we thought would be a classic in a field.

VOA: special.2010.04.19

It is like trying to establish which came first: The chicken or the egg.

BBC: Arab press lambasts Jenin report

The discovery of the statues raises an intriguing question - which came first, the statues or Ovid's famous poem?

BBC: 'Exceptional' find of Roman statues linked to poet Ovid

The big question is which came first: positive outlook as a result of a successful business or an innovative business?

FORBES: Innovation and Growth: Which Comes First, the Chicken or the Egg?