The core problem has to do with the novel's 9-year-old hero.

This gets to the core problem with the Bush approach to missile defense.

So in debating how to move forward, let's focus on the core problem.

Language study had always been one of the core problems for the mission.

But, in a way, the core problem is the same: pain.

That core problem was often at the heart of the two nations' disputes.

"This will help a little, but it doesn't address the core problem," he said.

The core problem of the entire project was the water supply to the depression.

At the end of the day, it always comes down the one core problem, the euro itself.

Population growth is the core environmental problem for most of the world.