It's a vital international problem that you have to solve.

It is the causation of images that is the vital problem.

The vital problem just now was to escape from the Sun's attraction.

He evinces neither power nor inclination to come to grips with any vital human problem.

At this point, however, a new and vital problem emerged.

Economic modernisation requires solutions to some vital problems, including tax administration.

Why not focus, some ask, on vital problems like crumbling schools and ratty textbooks?

Each nation solved this vital problem according to its traditions.

And vital problems they are, ones that have threatened America's crucial dominance in the quality-of-gadget wars.

As, therefore, almost all the issues have been exhausted, I shall confine myself to one vital problem.