Scientific proof of any of these speculations is at present impossible.
It seems appropriate that a chapter of history almost impossible to grasp would present impossible challenges, especially for young children.
Keats has no money to propose – this hesitation has its own delicious erotic charge – but then his terrible illness comes along, making living in an ecstatic present impossible.
A statement said: "The cancer is, in short, inoperable and will prove fatal in time, though it is at present impossible to measure life expectancy".
Whether this univariant melting reaction has the topology of co-precipitation (cotectic), or a reversal to resorptional (peritectic) occurs with decreasing XMg, it is at present impossible to ascertain.
A missed paycheck or an illness can present impossible choices.
I'm not sure what inspired me to do it; perhaps it was my lack of finances that made any other present impossible.
The ingenious twists and turns of an increasingly suspenseful plot (corruption in companies, governments, and families, presidential assassinations, murder cover-ups, kidnapping, political coups, nuclear and bio-chemical threats, treason, torture, familial betrayal) present impossible scenarios for Jack Bauer to overcome, let alone survive.
Katherine Tiedemann and Peter Bergen's "Revenge of the Drones," a report from the New America Foundation, has a particularly sensible discussion of a question that is, at present, impossible to answer (because no reporters are around): How many civilians have died in drone attacks in the Pakistani borderlands?
It is at present impossible to determine whether molecular chaperones are mostly helpers or examiners of mutated proteins because experiments showing either of these roles are very few.
Applying strict corrections for multiple testing would make investigations like the present impossible to perform, because a sample big enough to withstand such a correction procedure would probably never be possible to obtain.
