be sure about

However, others have argued that more comprehensive testing is required to be sure about an individual-s genetic makeup, which would raise concerns over cost and invasiveness.

No-one can be sure about this.

"Earth was probably a watery planet, like in the movie Waterworld, but without any oxygen in the atmosphere and without emergent crust. But, because that's so far back in time, we can't be really be sure about what it actually looked like," says Tod Waight.

On Saturday afternoon, Amaryllis Fox Kennedy, Mr. Kennedy’s daughter-in-law who is also his campaign manager, said in a lengthy post on the social media platform X that the news media “were sure about Aaron, now they’re sure about Nicole. Tomorrow they’ll be sure about someone else.”

And although Southern and Northern hemisphere populations of marine mammals don’t have much, if any contact, Johnson said the world is changing so quickly, we can’t really be sure about anything.