Many people found the objects and displays helped explain a subject that is hard to understand.

VOA: special.2009.12.01

Sometimes,financial news can be hard to understand.

VOA: special.2010.04.30

"I mean it's hard to even understand how biology was a science as we would recognize it today.

VOA: special.2009.12.01

It was hard for him to fully understand what he saw in her expression.

VOA: special.2009.09.05

Because if you just have random bones lying around, it's hard for someone to come in and look at it and understand what the animal looked like in its entirety.

VOA: standard.2009.12.08

Lee Smith says it has always been hard for Americans to understand exactly why peace in the Middle East is so elusive, and why violence and terrorism are so pervasive and persistent in the Arab world.

VOA: standard.2010.03.18