B2 不确定，前途未卜
If the future or success of someone or something is in doubt, it is unlikely to continue or to be successful.
The future of the stadium is in doubt because of a lack of money. 由于缺少资金，该体育馆能否建成还不确定。
Their long-term survival remains in doubt because of the twin disasters of habitat loss and climate change.
The outcome of these talks is now in doubt.
Tragically, this generation are inheriting a planet whose viability is in doubt.
Sadly, he's not the only potential team member whose fitness is in doubt.
See also: doubt noun