A big challenge has been to get the oil out.

No big challenge getting a 1026 on something like that.

Trying to run it is a big challenge to me.

And this, in its own way, is a big challenge for the political system.

In the early 2000s, this had been no big challenge.

Finally, I must say that 2003 will really be a big challenge.

His biggest challenge at the moment is to learn how to go to bed earlier!

That was the big challenge for us after the first record and the response to it.

The next big challenge is to figure out where to put the path.

But her biggest challenge will be to find a new public.