But the professor says it is difficult to find enough feathers from a single dinosaur to recreate all its colors.

VOA: special.2010.03.16

For example, celiac disease is difficult to identify because the signs of the disease are so common.

VOA: special.2009.04.14

For example,celiac disease is difficult to identify because the signs of the disease are so common.

VOA: special.2010.06.15

But it is difficult to read and judge a wave when it is near.

VOA: special.2009.03.17

Even today, it is difficult to walk or ride through the park.

VOA: special.2009.04.15

So it is difficult to see the animals in the sand.

VOA: special.2010.01.04

But it is difficult to put a price on troubled securities.

VOA: special.2009.01.30

It is difficult to tell exactly where the saying began.

VOA: special.2010.07.25

So when you talk to class four, he says,then it is difficult to teach the little kids in class one.

VOA: standard.2010.02.25

There is this audit and recount process. It is difficult to put a timeline to both of these activities at this point."

VOA: standard.2009.09.15

"I think one needs to recognize given the current state of relations it is difficult to describe it as a strategic one anymore.

VOA: standard.2009.10.27

He says it is difficult to know how the disease will evolve.

VOA: standard.2009.05.14

Smith says Turkey's position is difficult to sustain.

VOA: standard.2010.03.19

"Because there are only a couple of previous records of eruption at this particular volcano, it is difficult to judge either how long the activity will go on there, or how long the volcano might then be dormant before it goes active again."

VOA: standard.2010.04.15