That was a conjecture, not a fact.

那是个推测，不是事实。

There are several conjectures.

有几种推测。

Ozone creation is a very large-scale natural process and the importance of human-generated CFCs in reducing it is largely a matter of conjecture.

臭氧层的产生是一个大规模的自然过程，人类产生的氟氯碳化物对臭氧层的耗损很大程度上是一种推测。

He conjectured that some individuals may be able to detect major calamities.

他推测有些人也许能察觉到重大灾难。