Dark energy, however, is an unknown unknown.

但是，暗能量却是一个未知的未知。

youdao

The impact of the deep water deployment is definitely an unknown unknown, as it has not been used on anything like this scale before.

深海的处置措施施造成的影响显然是一个未知的未知，毕竟在此之前人们从没有处理过这么大规模的事故。

youdao

The $2 trillion in lending is going to unknown places in exchange for unknown collateral.

这2万亿美元的贷款将去未知的地方以换取未知的抵押品。

youdao

But now she is on her own, "with no direction home, like a complete unknown, like a rolling stone."

VOA: special.2009.06.21

- "She lived unknown and few could know"-- how can she be unknown if few know anything about her?

她不为人知地活着，鲜有人知道她“,如果有任何人知道关于她的任何事情,又怎么能说他不为人知呢？

耶鲁公开课 - 文学理论导论课程节选

A kind of a pin used to hold your cloak together, called a fibula, unknown in the previous period.

一种别住披风的别针,称之为扣针,这在之前的时期从未出现过

耶鲁公开课 - 古希腊历史简介课程节选

Hope speaks to the unknown and it is always the challenger who represents the unknown.

FORBES: Voter Enthusiasm Gap The Real Challenge To Obama Re-Election

But both RecA and RpoB had one branch that really was an unknown unknown.

ECONOMIST: A new domain of life

The goals of these trusts and foundations are unknown, and when they will be spent down also unknown.

FORBES: Marc Benioff: Billionaires Should Act Charitably Now, Not Later