Intolerance was perhaps the most difficult challenge to address.

The marketing is, the bigger a brand, the more difficult it is to reposition it.

That's a more difficult question...

Now, this one is a little bit trickier.

We tried to make it more difficult.

It's tougher on the outside now.

The future will be more unpredictable.

Let's do something a little more difficult.

And international support could be removed at any time.

But now we're going to make it more difficult.

New fungal infections are even scarier and might be harder to treat.

Yet, by switching off the lights, all we are doing is making it harder to see.

That makes my job more difficult, because, if I want to surprise them,

Next question, a little bit harder.

There are a bit harder issues.

Making it more difficult to capture him

It actually got harder.

Tonight, I will make it even more difficult.

Makes it more and more difficult to initiate actions.

Now let's make this a little bit more difficult.

Each time it becomes more difficult.

Another hypothesis is that it is actually intelligence that causes social relationships to become more complex, because intelligent individuals are more difficult to learn to know.

For some people we made it harder by hiding the instructions.

European officials will argue that their problem is more difficult.

Things became more difficult with the advent of the Great Depression.

And that's a much, much more difficult lesson to take into account.

So, let's do a second experiment. It's even more subtle than that one.

Beginners get the really simple sentences from the web and advanced users get the more complex ones.

Well, with hardware it's much more difficult.

For some people, we made it harder by hiding the instructions.

That one was way more difficult than I had expected.

Admiral Lord Horatio D'Ascoyne presented a more difficult problem.

Save you a couple of hours. Make it harder for the dogs.

That Khamenei is himself more of an ideologue makes that task doubly difficult for him.

That's why cancer is such a difficult disease to treat.

But governing the enlarged union has become more difficult and less efficient.

But success in Cairo might prove even more challenging.

However, the latter task would appear to be far more daunting than the former.

Yet the most difficult and divisive issues are still to be addressed.

So to make matters even more difficult, it's a very young planet.

Let's do another one, maybe one that seems a little bit more difficult.

These techniques were a lot harder to learn than people had anticipated.

Actually, I'll do even a slightly confusing one.

But if you carry on this way it becomes even more so.

The main thing that anyone accomplished by turning off the lights at nighttime for an hour was to make it harder to see.