It does present a challenge to industry, government and individual workers.

As such these foods present a challenge to those who have a professional interest in food.

The confrontation may present a new challenge to the Government.

Plus, boys present a different challenge, one that I like.

The first years of 21st century have also presented challenges.

The event seems certain to present a fresh challenge to the government, if only on a small scale.

School can also present a particular challenge for a child with type 1 diabetes.

And that, he said, presents a particularly difficult challenge for the Bush administration.

It does of course present a challenge to the underlying information and technology system.

The management of context in natural language understanding can present special challenges.