I suspected the constant challenge was more than just the difficulty of the work itself.

The question was, how far would these wives be able to bear the constant challenge?

The legal situation provided a constant challenge to the organizers and production staff.

For designers, it's a constant challenge of solving the same old problem.

It's been fun and a constant challenge to do this role.

Without constant challenges perhaps it is natural to lose some of our brain power.

Staying motivated is a constant challenge for anyone in training.

She was a constant challenge, and not an easy woman to live with.

The constant challenges and changes in the economic position of a business mean that employees are often forced to look around for other opportunities.

But maintaining the ship was a constant financial challenge for the foundation.